Permian Brachiopods of West Texas, III (PART 2 - PLATES) G. ARTHUR COOPER and RICHARD E. GRANT SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY NUMBER 19 SERIAL PUBLICATIONS OF THE SMITHSONIAN INSTITUTION The emphasis upon publications as a means of diffusing knowledge was expressed by the first Secretary of the Smithsonian Institution. In his formal plan for the Insti- tution, Joseph Henry articulated a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge." This keynote of basic research has been adhered to over the years in the issuance of thousands of titles in serial publications under the Smithsonian imprint, com- mencing with Smithsonian Contributions to Knowledge in 1848 and continuing with the following active series: Smithsonian Annals of Flight Smithsonian Contributions to Anthropology Smithsonian Contributions to Astrophysics Smithsonian Contributions to Botany Smithsonian Contributions to the Earth Sciences Smithsonian Contributions to Paleobiology Smithsonian Contributions to Zoology Smithsonian Studies in History and Technology In these series, the Institution publishes original articles and monographs dealing with the research and collections of its several museums and offices and of professional colleagues at other institutions of learning. These papers report newly acquired facts, synoptic interpretations of data, or original theory in specialized fields. These pub- lications are distributed by mailing lists to libraries, laboratories, and other interested institutions and specialists throughout the world. Individual copies may be obtained from the Smithsonian Institution Press as long as stocks are available. S. Dillon Ripley Secretary Smithsonian Institution SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY NUMBER 19 Permian Brachiopods of West Texas, III (PART 2-PLATES) G. Arthur Cooper and Richard E. Grant ISSUED DEC29T973 SMITHSONIAN INSTITUTION PRESS City of Washington 1975 Contents PLATES Page Heteralosia, Ctenalosia, and Liosotella 1300 Heteralosia 1302 Spuriosa and Heteralosia 1304 Heteralosia 1306 Heteralosia 1308 Ctenalosia 1310 Ctenalosia 1312 Acritosia 1314 Acritosia and Richthofenia 1316 Acritosia 1318 Acritosia 1320 Acritosia and Teguliferina 1322 Teguliferina 1324 Teguliferina 1326 Teguliferina 1328 Teguliferina 1330 Paucispinifera, Liosotella, Cooperina, Glyptosteges, and Horridonia 1332 Cooperina 1334 Cooperina 1336 Atelestegastus 1338 Clionosteges and Cooperina 1340 Limbella 1342 Limbella 1344 Limbella 1346 Limbella 1348 Paucispinifera, Cyclacantharia, Limbella, and Rhamnaria 1350 Edriosteges 1352 Edriosteges 1354 Edriosteges 1356 Edriosteges 1358 Edriosteges 1360 Edriosteges and Echinosteges 1362 Echinosteges 1364 Echinosteges 1366 Echinosteges 1368 Echinosteges 1370 Echinosteges 1372 Echinosteges 1374 Echinosteges 1376 Agelesia, Spyridiophora, and Cactosteges 1378 Xenosteges 1380 Hystriculina and Xenosteges 1382 Xenosteges 1384 Xenosteges 1386 Xenosteges 1388 Scapharina and Kutorginella 1390 Scapharina 1392 Scapharina 1394 iii 1V SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY Page Chonosteges 1396 Chonosteges 1398 Chonosteges 1400 Chonosteges 1402 Chonosteges, Yakovlevia, Echinosteges, Paucispinifera, Oncosarina, and Xenosteges . . 1404 Chonosteges 1406 Institella and Peniculauris 1408 Institella 1410 Institella 1412 Glyptosteges 1414 Glyptosteges 1416 Spyridiophora 1418 Spyridiophora 1420 Spyridiophora and Glyptosteges 1422 Craspedona 1424 Agelesia 1426 Ametoria and Ramavectus 1428 Limbella and Ramavectus 1430 Rhamnaria, Ramavectus, and Echinosteges 1432 Rhamnaria 1434 Rhamnaria 1436 Rhamnaria 1438 Rhamnaria 1440 Rhamnaria 1442 Rhamnaria 1444 Rhamnaria 1446 Rhamnaria 1448 Echinosteges and Rhamnaria 1450 Tschernyschewia 1452 Tschernyschewia and Strophalosia 1454 Scacchinella 1456 Scacchinella 1458 Scacchinella 1460 Scacchinella 1462 Scacchinella 1464 Scacchinella 1466 Scacchinella 1468 Scacchinella 1470 Scacchinella 1472 Scacchinella 1474 Scacchinella 1476 Scacchinella 1478 Scacchinella 1480 Scacchinella 1482 Dyoros (Dyoros), Scacchinella, Sestropoma, and Acritosia 1484 Hercosia I486 Hercosia 1488 Hercosia 1490 Hercosia 1492 Hercosestria and Hercosia 1494 Hercosia and Hercosestria 1496 Hercosestria 1498 Hercosestria 1500 Hercosestria 1502 Acritosia and Cyclacantharia 1504 Cyclacantharia 1506 Cyclacantharia 1508 Cyclacantharia 1510 NUMBER 19 Page Cyclacantharia 1512 Cyclacantharia 1514 Cyclacantharia 1516 Hercosia and Cyclacantharia 1518 Cyclacantharia 1520 Taphrosestria 1522 Taphrosestria 1524 Taphrosestria and Collumatus 1526 Collumatus and Sestropoma 1528 Sestropoma 1530 Acritosia, Cyclacantharia, and Sestropoma 1532 Acritosia, Hercosia, Teguliferina, Collumatus and Cyclacantharia 1534 Fimbrinia, Simplicarina, Oncosarina, and Costispinifera 1536 Fimbrinia and Rhytisia 1538 Kozlowskia, Costispinifera, and Simplicarina 1540 Kozlowskia 1542 Kozlowskia 1544 Hystriculina 1546 Bothrionia and Thamnosia 1548 Bothrionia 1550 Oncosarina and Bothrionia 1552 Costispinifera 1554 Costispinifera 1556 Costispinifera 1558 Elliottella 1560 Elliottella 1562 Oncosarina 1564 Hystriculina and Elliottella 1566 Echinauris 1568 Echinauris 1570 Echinauris 1572 Echinauris 1574 Echinauris 1576 Echinauris 1578 Echinauris 1580 Echinauris 1582 Echinauris 1584 Echinauris 1586 Echinauris 1588 Echinauris 1590 Echinauris 1592 Echinauris 1594 Echinauris 1596 Echinauris 1598 Kutorginella 1600 Kutorginella 1602 Kutorginella 1604 345- Thamnosia 1606 Thamnosia 1608 Thamnosia 1610 Thamnosia 1612 Thamnosia 1614 Kutorginella 1616 Thamnosia and Rhamnaria 1618 Bathymyonia and Waagenoconcha 1620 Hercosia, Juresania, and Bathymyonia 1622 Waagenoconcha 1624 Waagenoconcha 1626 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY Page Waagenoconcha 1628 Waagenoconcha 1630 Kochiproductus 1632 Kochiproductus 1634 Kochiproductus 1636 Kochiproductus 1638 Rhamnaria and Kochiproductus 1640 Dasysaria 1642 Dasysaria 1644 Dasysaria and Nudauris 1646 Xestosia and Nudauris 1648 Echinauris, Xestosia, and Nudauris 1650 Nudauris 1652 Nudauris 1654 Nudauris 1656 Nudauris and Xestosia 1658 Nudauris 1660 Rugatia 1662 Rugatia 1664 Rugatia 1666 Rugatia 1668 Rugatia 1670 Rugatia and Reticulata 1672 Spinarella 1674 Spinarella 1676 Spinarella 1678 Xestosia 1680 Xestosia and Reticulata 1682 Spinifrons 1684 Spinifrons 1686 Reticulatia, Antiquatonia, Calliprotonia, and Echinaria 1688 Spinifrons 1690 Spinifrons 1692 Spinifrons 1694 Spinifrons and Antiquatonia 1696 Antiquatonia 1698 Reticulatia 1700 Reticulatia 1702 Peniculauris 1704 Peniculauris 1706 Peniculauris 1708 Peniculauris 1710 Peniculauris 1712 Peniculauris 1714 Peniculauris 1716 Peniculauris 1718 Peniculauris 1720 Peniculauris 1722 Peniculauris 1724 Peniculauris 1726 Peniculauris 1728 Peniculauris 1730 Anemonaria 1732 Liosotella 1734 Nudauris, Echinauris and Liosotella 1736 Liosotella 1738 Liosotella and Grandaurispina 1740 Liosotella 1742 NUMBER 19 Vll Page Liosotella 1744 Liosotella 1746 Liosotella 1748 Paucispinifera 1750 Paucispinifera 1752 Paucispinifera and Oncosarina 1754 Paucispinifera 1756 Paucispinifera 1758 Paucispinifera 1760 Paucispinifera 1762 Paucispinifera 1764 Paucispinifera 1766 Paucispinifera 1768 Polymorpharia 1770 Cancrinella 1772 Cancrinella 1774 Cancrinella and Grandaurispina 1776 Linoproduclus 1778 Linoproduclus 1780 Compressoproductus and Linoproductus 1782 Yakovlevia and Liraria 1784 Grandaurispina 1786 Grandaurispina 1788 Grandaurispina 1790 Grandaurispina 1792 Grandaurispina 1794 Grandaurispina 1796 Grandaurispina 1798 Grandaurispina 1800 Grandaurispina 1802 Holotricharina 1804 Echinaria, Holotricharina, Hystriculina and Calliprotonia 1806 Acanthocrania, Paucispinifera, Elliottella, Liosotella, Megousia, and Holotricharina 1808 Megousia and Kozlowskia 1810 Megousia 1812 Megousia 1814 Megousia 1816 Megousia 1818 Megousia and Yakovlevia 1820 Megousia, Grandaurispina, Linoproductus, Antiquatonia, and Kozlowskia 1822 Compressoproductus 1824 Striatifera and Compressoproductus 1826 Compressoproductus 1828 Compressoproductus 1830 Compressoproductus 1832 Compressoproductus 1834 Compressoproductus 1836 Compressoproductus 1838 Compressoproductus and Striatifera 1840 Institella, Megousia, Compressoproductus, and Striatifera 1842 Compressoproductus and Polymorpharia 1844 Striatifera 1846 Siphonosia 1848 Siphonosia, Megousia, and Undellaria 1850 Horridonia, Echinauris, Institella, Glyptosteges, Siphonosia, and Nudauris 1852 Yakovlevia 1854 Yakovlevia 1856 Yakovlevia 1858 Vlll SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY Page Yakovlevia 1860 Yakovlevia 1862 Yakovlevia 1864 Spyridiophora, Paucispinifera, Limbella, Striatifera, and Orthotichia 1866 Echinauris, Sestropoma, Paucispinifera, and Rugoclostus 1868 Chonetinetes 1870 Chonetinetes, Chonetinella, and Sulcataria 1872 Chonetinella and Leurosina 1874 Chonetinella and Sulcataria 1876 Dyoros (Dyoros) 1878 Dyoros (Dyoros) 1880 Dyoros (Dyoros) 1882 Dyoros (Dyoros) 1884 Dyoros (Dyoros) 1886 Dyoros (Dyoros) 1888 Dyoros (Dyoros) and Dyoros (Lissosia) 1890 Dyoros (Lissosia) 1892 Dyoros (Lissosia) and Dyoros (Tetragonetes) 1894 Dyoros (Tetragonetes) 1896 Dyoros (Tetragonetes), Lissochonetes, and Quadrochonetes 1898 Dyoros (Tetragonetes) and Undulella 1900 Micraphelia 1902 Leurosina 1904 Leurosina and Dyoros (Tetragonetes) 1906 Mesolobus?, Rugaria, and Neochonetes 1908 Neochonetes, Dyoros (Tetragonetes), and Lamellosia 1910 498 Rugaria, Leurosina, Dyoros (Tetragonetes), Dyoros (Dyoros) and "Chonetes" 1912 Dyoros (Tetragonetes) and Rugaria 1914 Chonetinella, Dyoros (Dyoros), and Leurosina 1916 Dyoros (Dyoros), Chonetinella, and Micraphelia 1918 Quadrochonetes, Undulella, Dyoros (Lissosia), Dyoros (Dyoros), and Chonetinetes . . . 1920 NUMBER 19 PLATES 192-502 1300 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 192 Heteralosia, Ctenalosia, and Liosotella Heteralosia vidriensis, new species: 1-6, Interior, side, anterior, ventral, and posterior views, X 2, and ventral view, x 1, of a large pedicle valve, paratype USNM 152632d; 7, 8, interior and exterior, X 2, of a brachial valve, paratype USNM 152632b; 9, 10, exterior, X 2, and interior, X 3, of another brachial valve, showing bilobed cardinal process and dental sockets, paratype USNM 152632h. [Cathedral Mountain Formation, USNM 721u.] Heteralosia magnispina, new species: 11-13, Dorsal, side, and ventral views of a complete indi- vidual, X 2, holotype USNM 151272e; 14, interior of the brachial valve, x2, paratype USNM 151272f. [Cherry Canyon Formation (Getaway Member), USNM 728.] 15, 16, Side and ventral views of a pedicle valve, X 2, paratype USNM 151289a; 17-19, side, interior, and ventral views of another pedicle valve, x 2, paratype USNM 151289b. [Cherry Canyon Formation (Getaway Member), AMNH 519.] Ctenalosia rotunda, new species: 20-22, Interior, X 3, exterior, X 2, and posterior X 3, of a brachial valve, showing adductor platforms, paratype USNM 154121a; 23-25, posterior and interior, X 3, and exterior, X 2, of another brachial valve, showing brachial ridges and adductor platforms, paratype USNM 154121b. [Bell Canyon Formation (Hegler Member), USNM 732a.] Ctenalosia primitiva, new species: 26, Two immature specimens attached to the interior of a Derbyia brachial valve, X 3, paratype USNM 151249d; 27, 28, exterior, X 3, and interior, x 4, of the brachial valve, paratype USNM 151249c; 29-32, dorsal, ventral, side, and posterior views of the holotype, X 2, USNM 151249a. [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] 33, 34, Interior and exterior, X 4, of another brachial valve, paratype USNM 151267. [Neal Ranch Formation (bed 4), USNM 721g.] Ctenalosia rotunda, new species: 35, 36, Interior, X 4, and posterior, X 6, of a brachial valve, holotype USNM 152645c; 37-41, ventral, side, anterior, dorsal, and posterior views, X 4, of a complete specimen, paratype USNM 152645b; 42^5, anterior, dorsal, side, and ventral views of a complete specimen, x 4, showing the exterior view of the brachial valve in figure 35, holotype USNM 152645c. [Bell Canyon Formation (Hegler Member), AMNH 635.] Liosotella rotunda, new species: 46-51, Dorsal, side, anterior, ventral, and posterior views, X 1, and ventral view, X 2, of a complete specimen, holotype USNM 154122a; 52-56, side, anterior, interior, ventral, and posterior views of a pedicle valve, X 1, paratype USNM 154122b; 57, in- terior of the brachial valve, X 2, paratype USNM 154122c. [Road Canyon Formation, USNM 732j.] NUMBER 19 1301 PLATE 192.-Heteralosia, Ctenalosia, and Liosotella .^io^.;>. ^ ' 30 i&MimW io ' W*M$\ W^Pr M V: 18 nHJH *œ* '! 19 / 25 31 - / 32 ^®a 28 ^=> 33 1302 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 193 Heteralosia Heteralosia species 1:1, Dorsal, posterior, side, anterior, and ventral views of a complete specimen, X 1, figured specimen USNM 152631; 2, dorsal view of the preceding specimen, x 2. [Cathedral Mountain Formation, USNM 702.] Heteralosia species 7: 3-7, Posterior, side, ventral, anterior, and interior views of a pedicle valve with rectangular outline, X 2, figured specimen USNM 151274a; 8, interior of a brachial valve, X 2, USNM 151274b. [Bone Spring Formation, locality 728f.] Heteralosia species 4: 9, Ventral, posterior, anterior, and side views of a pedicle valve, X 2, figured specimen USNM 151293a. [Bone Spring Formation, AMNH 628.] Heteralosia species 6: 10, Ventral, posterior, and side views of a pedicle valve, X 2, figured specimen USNM 152636. [Bell Canyon Formation (Rader Member), AMNH 410.] Heteralosia species 7: 11, Exterior of a rectangular pedicle valve, X 2, figured specimen USNM 151274c. [Bone Spring Formation, USNM 728f.] Heteralosia 77iagnispina, new species: 12, 13, Interior and exterior of a brachial valve, X 2, paratype USNM 154119. [Bell Canyon Formation (Lamar Member), USNM 738b.] Heteralosia species 2: 14, Dorsal and ventral views, X 2, of a small specimen, figured specimen USNM 154120. [Road Canyon Formation, USNM 707e.] Heteralosia tenuispina, new species: 15-17, Ventral, anterior, and posterior views of a pedicle valve, x 2, paratype USNM 152634a; 18, 19, exterior and interior of a pedicle valve, X 2, holotype USNM 152634b; 20-23, interior, anterior, posterior, and ventral views, of a young pedicle valve, x 2, paratype USNM 152634c; 24, 25, exterior and interior of a brachial valve, X 2, showing slightly developed cardinal process, paratype USNM 152634d. [Bell Canyon Formation (Hegler Member), USNM 731.] Heteralosia paucispinosa, new species: 26, 27, Interior and exterior of a brachial valve, X 2, showing cardinal process, paratype USNM 155030. [Bell Canyon Formation (Hegler Member), USNM 731.] Heteralosia vidriensis, new species: 28-33, Ventral view, X 1, and ventral, anterior, posterior, side; and interior views, X 2, of a large pedicle valve, paratype USNM 152632c; 34-37, interior, side, posterior, and ventral views of another pedicle valve with most of its spines stripped away, X 2, paratype USNM 152632f; 38-43, ventral view, X 1, and ventral, interior, anterior, side, and posterior views, X 2, of another pedicle valve preserving scattered spines, paratype USNM 152632a; 44, ventral, anterior, posterior, and side views of a well preserved pedicle valve, X 2, holotype USNM 152632g. [Cathedral Mountain Formation, USNM 721u.] Heteralosia hystricula (Girty): 45, 46, Posterodorsal and interior views of a large, old brachial valve, X 3, showing strongly pustulosc interior, brachial ridges, and strongly lobed cardinal process, hypotype USNM 154115-1. [Word Formation (Willis Ranch Member), USNM 706.] NUMBER 19 1303 PLATE 19S.-Heteralosia Q>^;$ BET '~$jœ& ^ ^ Fj&I ^" fc-^ 1 il Li ^ 13 12 9 wvL5. 'l6^ J  17 23 26 1304 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 194 Spuriosa and Heteralosia Spuriosa circularis, new species: 1-4, Ventral, side, dorsal, and anterior views of a complete specimen, X 2, holotype USNM 153490a; 5, 6, interior and exterior of the brachial valve of the holotype, X 6, 7-11, Interior, posterior, anterior, and ventral views of a pedicle valve, X 2, paratype USNM 153490b; 12, 13, posterior and exterior views of the brachial valve of the pre- ceding specimen, x 4; 14, 15, exterior and interior views of the preceding specimen, X 6, showing median ridge. [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] Heteralosia hystricula (Girty): 16, Anterior view, X 2, of a large pedicle valve showing its rhizoid spines, hypotype USNM 153581b; 29, pedicle valve of Paucispinifera encrusted by individuals of Heteralosia, x 2, showing mode of attachment, hypotype USNM 123891g. [Word Formation (Willis Ranch Member), USNM 706e.] Interior of a pedicle valve of Costispinifera, X 2, occupied by Heteralosia and showing the long ornament spines, hypotype USNM 154115a; 19, another Costispinifera pedicle valve, X 2, occupied by Heteralosia with long ornament spines, hypotype USNM 154115b; 20, 21, dorsal and ventral views of a complete specimen, x 1, hypotype USNM 154115c; 22-25, dorsal, an- terior, ventral, and side views, X 2, of the preceding hypotype; 28, dorsal valve of Costispinifera occupied by Heteralosia, X 1, hypotype USNM 154115d. [Word Formation (Willis Ranch Mem- ber), USNM 706.] Heteralosia on Dyoros, X 1, hypotype USNM 154116a; 26, Interior of a large Paucispinifera, X 2, showing a number of Heteralosia, hypotype USNM 154116d; 27, Exterior of a Paucispinifera pedicle valve encrusted by Heteralosia, X 1, hypotype USNM 154116f; 30, 31, brachial valve of Paucispinifera with attached Heteralosia and young Cyclacantharia, X 1, X 2, hypotype USNM 154116e. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1305 PLATE 194.-Spuriosa and Heteralosia 1306 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 195 Heteralosia Heteralosia hystricula (Girty): 1, Interior, interior tilted posteriorly, side, posteroventral, and anterior views of a large pedicle valve, X 1, hypotype USNM 154117c; 2, interior, X 2, of the preceding specimen, showing the teeth; 3-6, anterior, ventral, side, and posterior views of the preceding specimen showing cicatrix of attachment; 7, group of young specimens attached to a productid shell, x 2, hypotype USNM 154117a. [Word Formation (Willis Ranch Member), USNM 706e.] 8-10, Dorsal, ventral, and posterior views of a complete specimen, X 1, hypotype USNM 154115e; 20, ventral view of a pedicle valve attached to the umbo of a productid shell, x 1.5, hypotype USNM 154115f; 27, 28, interior, X 3 and exterior X 2 of a brachial valve, hypotype USNM 154115g; 29, 30, interior, X 3, and exterior, X 2, of another brachial valve with lobate cardinal process, hypotype USNM 154115h; 31, 32, interior, X 3, and exterior, x 2, of another brachial valve with strongly lobate cardinal process, hypotype USNM 154115i; 33, 34, interior, X 3, and exterior, X 2, of a brachial valve of large size but nonlobate cardinal process, hypotype USNM 154115j; 35, 36, interior, X 3, and exterior, X 2, of an obese brachial valve with strongly lobate cardinal process, hypotype USNM 154115k. [Word Formation (Willis Ranch Member), USNM 706.] 11-14, Posterior, anterior, dorsal, and side views, X 2, of an obese specimen, hypotype USNM 154118a; 15-19, posterior, ventral, dorsal, anterior, and side views of the preceding specimen, X 1; 21, 22, ventral valve, X 1, X 2, attached to a lyttoniid and showing the myophragm, hypo- type USNM 154118b; 23, 24, dorsal view, X 1, X 2, of a young specimen with brachial valve in place, hypotype USNM 154118c; 25, 26, interior and exterior of a brachial valve, X 2, showing elevated adductor platforms and unlobed cardinal process, hypotype USNM 154118d; 43, two interior views, X 1, and interior, ventral, and side views, X 2, of a specimen showing myophragm and rhizoid spines, hypotype USNM 154118e. [Word Formation (China Tank Member), USNM 706c] 37, 38, Interior and exterior views, X 2, of a brachial valve with unlobed cardinal process, hypotype USNM 154116b; 39, posterodorsal view of the preceding specimen, X 3, showing myophore; 40, 41, exterior and interior of another brachial valve, X 2, but having a strongly lobcd cardinal process, hypotype USNM 154116c; 42, posterodorsal view of the preceding hypo- type, X 3, showing the lobed myophore. [Word Formation (lens between Willis Ranch and Appel Ranch members) , USNM 706b.] NUMBER 19 1307 PLATE 195.-Heteralosia ttu< i^Mli o<& 1308 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 196 Heteralosia Heteralosia paucispinosa, new species: 1-3, Exterior and interior, X 2, and posterodorsal view, X 3, of a brachial valve showing a slender, unlobed cardinal process, paratype USNM 154129a; 4-6, exterior, interior, X 2, and posterodorsal view of another brachial valve, showing a slender unlobed cardinal process, paratype USNM 154129b; 8-11, anterior, posterior, side, and interior of a pedicle valve, X 2, showing few, stout, ornament spines, holotype, USNM 154129c; 12-15, ventral, posterior, side, and interior views, X 2, of another pedicle valve, paratype USNM 154129e; 16-19, ventral, posterior, side, and interior views of a pedicle valve, X 2, paratype USNM 154129d; 20, ventral view of a young pedicle valve, X 2, having few ornament spines, paratype USNM 154129f; 21-23, side, posterior, and ventral views of a large pedicle valve, X 2, paratype USNM 154129g. [Bell Canyon Formation (Hegler Member), USNM 731.] 7, Interior of a pedicle valve attached to a small coral, X 1.5, paratype USNM 154130. [Bell Canyon Formation (Hegler Member), USNM 732a.] 24, 25, Interior and exterior, of a brachial valve with brachial ridges, X 2, paratype USNM 151280a; 26, 27, exterior, X 2, and interior, X 3, of another brachial valve having the anterior ends of the brachial ridges strongly elevated, paratype USNM 151280c; 28-31, ventral, side, posterior, and interior views, X 2, of a pedicle valve, paratype USNM 151280b. [Bell Canyon Formation (Lamar Member), AMNH 38.] 32, 33, Exterior, x 2, and interior x 3, of a brachial valve having an unlobed cardinal process, paratype USNM 154131a; 34-36, posterior, anterior, and side views of a pedicle valve, X 2, showing few, long ornament spines, paratype USNM 154131b. [Bell Canyon Formation (Rader Member), AMNH 410.] 37, Interior of a brachial valve, x 2, showing a slightly lobed cardinal process, paratype USNM 154132a; 38-40, posterior, side, and ventral views, x 2, of a pedicle valve, paratype USNM 154132b. [Bell Canyon Formation (Hegler Member), AMNH 635.] 41, 42, Interior and side views of a pedicle valve attached to an Ombonia valve, X 2, paratype USNM 154133. [Bell Canyon Formation (Lamar Member), USNM 728p.] Heteralosia magnispina, new species: 43, 44, Interior of the brachial valve, X 3, X 2, showing thick median ridge, and stout cardinal process, paratype USNM 151272h; 45-47, dorsal, ventral, and side views, X 2, of the paratype, USNM 151272i; 48-50, interior, side, and ventral views, X 2, of a pedicle valve, showing teeth and myophragm, paratype USNM 151272J; 51-53, side, ventral, and dorsal views, X 2, of a complete specimen, showing large cicatrix, paratype USNM 151272k; 54, interior of a pedicle valve showing attachment by rhizoid spines on all sides, X 2, paratype USNM 151272-1; 55, interior of a brachial valve, X 3, showing median septum, pustulose inner region, and narrow cardinal process, paratype USNM 151272c; 56-58, posterior, x 3, and exterior and interior, X 2, of a brachial valve with very slender cardinal process, paratype USNM 151272g; 59, 60, interior and exterior, x 2, of another brachial valve with slender cardinal process, paratype USNM 151272c!; 61-63, ventral, side, and dorsal views of the paratype USNM 151272m; 64, posterior of a pedicle valve, X 2, showing the interarea and teeth, paratype USNM 151272n; 65-67, interior, side, and ventral views, x 2, of a small pedicle valve, para- type USNM 151272o. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1309 PLATE 196.-Heteralosia 1310 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 197 Ctenalosia Ctenalosia fixata Cooper and Stehli: 1, Ventral valve, X 2, fixed to a bryozoan and showing teeth and myophragm, hypotype USNM 154123. [Word Formation (Appel Ranch Member), USNM 706d.] 2-5, Ventral, dorsal, posterior, and side views of a small individual, X 2, hypotype USNM 154124a; 6, 7, interior of the brachial valve, X 3 and exterior, x 2, showing a large, strongly lobate cardinal process, hypotype USNM 154124b. [Word Formation (Appel Ranch Member), USNM 722t.] 8-10, Exterior and interior, X 2, and interior, X 3, of a brachial valve with brachial ridges, hypotype USNM 154125c; 11, 12, side and dorsal views, X 2, of a specimen preserving its rhizoid spines, hypotype USNM 154125b; 13-15, side and interior views, X 2, and interior X 3, of a large pedicle valve showing the myophragm and hinge denticles, hypotype USNM 154125a; 16-19, side, dorsal, anterior, and posterior views, X 2, of a complete specimen devoid of spines, hypotype USNM 152642a; 20, 21, cluster of pedicle valves attached to a pectenoid pelecypod valve, X 1, X 2, hypotype USNM 152642b. [Word Formation (China Tank Member), USNM 706c] 22-24, Anterior and interior views, X 2, and anterior, X 1, of a ventral valve, showing mode of attachment and myophragm, hypotype USNM 154126a; 25, 26, small cluster of pedicle valves attached together, X 1, X 2, hypotype USNM 154126b; 27, 28, exterior, x 2, and interior, x 3, of a brachial valve, showing moderately lobed cardinal process and brachial ridges, hypotype USNM 154126c [Word Formation (Appel Ranch Member), USNM 719z.] 29, 30, Exterior and interior, X 2, of brachial valve having a cardinal process without marked lobation, hypotype USNM 154127a; 31, 32, exterior and interior of another brachial valve, X 2, showing thickened adductor patches, hypotype USNM 154127b; 33, 34, pedicle valve attached with a young Cyclacantharia, x 1, X 2, hypotype USNM 154127c [Word Formation (Appel Ranch Member), USNM 7l5i.] 35-37, Interior, and exterior, X 2, and posterior, x 3, views showing small, lobate cardinal process, hypotype USNM 154128a; 38-41, exterior and anterior, x 2, and posterior and interior, X 3, views showing denticles, adductor platforms, and large lobate cardinal process, hypotype USNM 154128b; 42-45, posterior, exterior, and interior, X 2, and direct posterior, x 3, views of a brachial valve having a strongly lobate cardinal process, hypotype USNM 154128c; 46-48, anterior and exterior, X 2, and interior, x 3, views, showing strong median fold, hypotype USNM 154128d; 49-52, exterior and anterior, X 2, and posterior and interior X 3, views, showing anterior fold and widely lobate cardinal process, hypotype USNM 154128e; 53-55, in- terior, side, and partial side views, X 2, of a pedicle valve attached to a crinoid stem, hypotype USNM 154128f; 56, ventral or anterior view of a specimen attached by rhizoid spines and showing the costellae on the surface, x 2, hypotype USNM 154128g; 57-59, ventral, dorsal, and side views, X 2, of a complete specimen, hypotype USNM 154128h; 60-62, interior, anterior, and side views of a pedicle valve, X 2, showing myophragm, costellae, and rhizoid spines, hypotype USNM 154128i; 63-64, interior and posterior of a specimen attached by nearly its entire surface, X 2, hypotype USNM 154128J; 65, interior of an attached pedicle valve, X 2, showing a thick myophragm, hypotype USNM 154128k. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1311 PLATE 197. -Ctenalosia 1312 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 198 Ctenalosia Ctenalosia transversa, new species: 1, 2, Dorsal view of a complete specimen, X 1, X 2, holotype USNM 152644d; 3, 4, interior of two attached pedicle valves, x 2, X 1, paratypes USNM 152644a, b; 5-7, anterior, interior, and side views of a pedicle valve attached to shell of Derbyia, X 2, paratype USNM 152644e; 8, 9, interior of another pedicle valve, X 2, and X 1, paratype USNM 152644c; 10, exterior of the previous specimen, X 1.5, showing a group of pedicle valves attached to the dorsal valve of Bathymyonia; 18, 19, two brachial valves of Bathymyonia, X 1.5, with clusters of attached Ctenalosia, paratypes USNM 152644g, h. [Park City Formation (Franson Member), USNM 762.] 11-13, Exterior, X 2, and posterior and interior, X 3, views, showing lobate cardinal process and adductor platforms, paratype USNM 154134a; 14-16, exterior, x 2, and interior and posterior, X 3, views, showing large cardinal process, adductor platforms and brachial ridges, paratype USNM 154134b; 17, interior of another brachial valve with lobate cardinal process and adductor platforms, X 3, paratype USNM 154134c [Park City Formation (Franson Member), USNM 760.] NUMBER 19 1313 PLATE 198,-Ctenalosia r.#> m-:,?> r:mr^:\ 1314 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 199 Acritosia Acritosia magna, Cooper and Grant: 1, 2, Side and dorsal views of a pedicle valve, X 1, paratype USNM 154043a; 3-5, posterior, apertural, and side views of a young specimen, X 1, paratype USNM 154043b. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] 6-8, Anterior, dorsal, and side views of a specimen with brachial valve in place, X 1, para- type USNM 151734; 28, 29, apertural and side views of a specimen with brachial valve attached in a cluster of Fissispongia, holotype USNM 151735a. [Neal Ranch Formation (bed 9 of Cooper), USNM 701 g.] 9, 10, Apertural and anterior views of a pedicle valve, x 1, paratype USNM 154044a; 11, 12, dorsal and apertural views of a specimen with brachial valve in place, X 1, paratype USNM 154044b; 13, side view of a large individual, X 1, paratype USNM 154044d; 14, side view of another pedicle valve, x 1, showing thin, round attachment spines, paratype USNM 151737e. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701h.] 15, 16, Apertural and side views of a young specimen with brachial valve in place, x 1, paratype 151739f; 17-19, interior, X 2, and interior and exterior, X 1, of the brachial valve, paratype USNM 151738; 20-22, apertural, anterior, and side views of a small individual, x 1, holotype USNM 151739a; 23, 24, side and anterior views of a large individual, X 1, paratype USNM 151739b; 25, anterior view of a short, squat specimen, x 1, paratype USNM 151739e; 26, 27, side and apertural views, X 1, of a large adult, paratype USNM 151739h. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] NUMBER 19 1315 PLATE 199.-Acritosia 1316 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 200 Acritosia and Richthofenia Acritosia silicica, new species: 1, 2, Side and apertural views of a pedicle valve, X 1, paratype USNM 152687b; 3-5, anterior, side, and dorsal (apertural) views of a complete specimen, X 1, paratype USNM 152687g; 6-8, side, dorsal, and anterior views of a small individual elongated by crowding, x 1, paratype USNM 152687q; 9-11, side, anterior, and dorsal views of another but normally shaped complete specimen, x 1, paratype USNM 152687a; 12, 13, dorsal and ventral views of two attached specimens, X 1, paratype USNM 152687s; 14, 15, dorsal and ventral views of another two attached specimens, X 1, paratype USNM 152687t; 16-18, side, anterior, and dorsal views of a. large pedicle valve, x 1, paratype USNM 152687d; 19-21, dorsal, side, and an- terior views of a large, normal, complete specimen, x 1, paratype USNM 152687h; 22-24, dorsal, side, and anterior views of a large attached specimen, showing endospines and attachment spines, X 1, paratype USNM 152687o; 25, 26, anterior view of a broken specimen, X 1, X 2, showing brachial valve in place, paratype USNM 152687v; 27, 28, ventral view of another broken speci- men, X 1, X 2, showing the brachial valve in place and the position of the cardinal process, paratype USNM 152687u; 29, small group of specimens attached to a large Composita, X 1, paratype USNM 152687x. [Hueco Formation, USNM 725b.] Acritosia teguliferoides (R. E. King): 30-32, Side, anterior, and dorsal (apertural) views of a pedicle valve, x 1, showing the mass of round, slender rhizoid spines, hypotype USNM 154049a; 33, 34, another attached specimen in anterior and partial dorsal views, x 1, hypotype USNM 154050a. [Bone Spring Formation, USNM 728e.] Richthofenia species: 35-37, Three views of a specimen longitudinally broken, X 1, showing the abundance of vesicular plates in the body of the cup, and the myocoelidium, figured specimen USNM 154051b; 38, apical or ventral view of another specimen, X 1, figured specimen USNM 154051a; 39, 40, dorsal and anterior views of the myocoelidium, X 1, hypotype USNM 15405H; 41, side view of a nearly complete specimen, X 1, hypotype USNM 154051c [Sanwans, Salt Range, Pakistan.] NUMBER 19 1317 PLATE 200.-Acritosia and Richthofenia 1318 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 201 Acritosia Acritosia peculiaris, new species: 1-3, Side, dorsal, and apertural views of a large, well-formed individual, x 1, holotype USNM 151756a; 4-6, interior and exterior, x 1, and exterior, x 2, showing spines of the brachial valve of the preceding specimen; 7, 8, side and apertural views of a young specimen, x 1, paratype USNM 151756b. [Skinner Ranch Formation (Poplar Tank Member), USNM 707ha.] 9, 10, Side and apertural views of a young specimen, x 1, showing spines on anterior side, paratype USNM 154045a; 11-13, apertural, anterior, and side views of a pedicle valve, X 1, paratype USNM 154045b; 14-16, side, apertural, and anterior views of a small specimen with both valves, X 1, paratype USNM 154045e; 17-19, side, anterior, and apertural views, and apertural view tilted to show adductor callosity, x 1, paratype USNM 154045c; 20, apertural view of a complete specimen, x 1, paratype USNM 154045h; 21,-22, apertural view, showing adductor platform, and side view, X 1, paratype USNM 154045d; 23, brachial valve interior X 2, paratype USNM 154045f; 24, 25, brachial valve interior, X 1, X 2, showing cardinal process and endospines, paratype USNM 154045g. [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] 26-28, Anterior, apertural, and side views of a pedicle valve, X 1, paratype USNM 154046a; 29-31, side, apertural, and anterior views of a specimen with brachial valve in place, X 1, paratype USNM 154046b; 32, 33, anterior and side views of a small individual, x 1, paratype USNM 154046d. [Bone Spring Formation, USNM 725c] 34, 35, Side and anterior views, X 1, of a large individual, paratype USNM 151776a; 36, 37, side and anterior views of an attached specimen showing rhizoid spines, X 1, paratype USNM 151776b. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707g.] 38-41, Interior and exterior views, x 1, and interior and side views, X 2, of a brachial valve showing cardinal process, paratype USNM 154048. [Hess Formation (top), USNM 726n.] 42, 43, Interior of a broken specimen, x 1, X 2, showing the brachial valve in place, paratype USNM 154047; 44, 45, interior of the piece detached from the preceding specimen, x 1, X 2, showing spines on cup rim and ends of rhizoid spines inside the cup. [Skinner Ranch Formation (Sullivan Peak Member), USNM 722h.] NUMBER 19 1319 PLATE ZO\.-Acritosia 39 1320 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 202 Acritosia Acritosia teguliferoides (R. E. King): 1, 2, Interior and exterior, X 1, of a brachial valve, hypotype USNM 154049b; 3, 4, interior and side of the preceding brachial valve, X 2, showing cardinal process and protective endospines; 5, 6, interior and exterior, x 1, of another brachial valve, hypo- type USNM 154049c; 7, 8, interior and side, x 2, of the preceding brachial valve; 16-18, anterior, side, and dorsal (apertural) views of a specimen with brachial valve in place, X 1, hypotype USNM 154049d; 19-21, anterior, dorsal views of a pedicle valve, X 1, showing granulose interior, hypotype USNM 154049f; 22-24, anterior, side, and dorsal views of another specimen with its rhizoid spines, X 1, hypotype USNM 154049h; 25-27, side, dorsal, and anterior views of a small, squat specimen with rhizoid spines, X 1, hypotype USNM 154049i; 29, dorsal view of pre- ceding specimen, X 2, showing granular exterior of brachial valve; 29-31, anterior side, and dorsal views of a small complete specimen, X 1, hypotype USNM 154049k; 32, dorsal view of the preceding specimen, x 2, showing granular brachial valve and rhizoid spines; 33, 34, dorsal and ventral (apical) views of a small cluster, X 1, showing attachment by round, slender spines, hypotype USNM 154050b; 35, 36, anterior and dorsal views of another small cluster, x 1, hypo- type USNM 154050c; 37, 38, side and ventral (apical) views of three attached specimens, X 1, hypotype USNM 154050d; 39, 40, anterior and dorsal views of a specimen, X 1, showing its strong and numerous attachment spines, hypotype USNM 154050e; 41, 42, ventral (apical) and side views of a specimen, x 1, showing spine bases, hypotype USNM 154050f. [Bone Spring Formation, USNM 728e.] 9, 10, Ventral and anterior views of a pedicle valve, X 1, hypotype USNM 154052a; 11, 12, dorsal and anterior views of an elongated specimen, x 1, hypotype USNM 154052b; 13, 14, dorsal and anterior views of a specimen with brachial valve in place, X 1, hypotype USNM 154052d; 15, anterior view of another pedicle valve, X 1, hypotype USNM 154052c. [Skinner Ranch Formation (base), USNM 705a.] Acritosia solida, new species: 43-45, Dorsal, side, and anterior views of a pedicle valve, X 1, paratype USNM 15I741e; 46-48, side, anterior, and dorsal (apertural) views of another pedicle valve, x 1, paratype USNM 151741b; 49, imperfect specimen, showing the cardinal process of the brachial valve through a break in the anterior side, X 1, paratype USNM 151741g; 50-52, dorsal, anterior and side views of a small specimen with long protective spines, x 1, paratype USNM 151741c; 53-55, anterior, side, and dorsal views of a moderately wide cup, X 1, paratype USNM 151741a; 56-58, side, dorsal, and anterior views of a well formed cup, X I, para- type USNM 151740a; 59-61, dorsal, anterior, and side views of a large, well formed cup, x 1, holotype USNM 151740b. [Hess Formation (Taylor Ranch Member), USNM 702d.] NUMBER 19 1321 PLATE ZOZ-Acritosia 1322 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 203 Acritosia and Teguliferina Acritosia teguliferoides (R. E. King): 1, 2, Side and anterior views of a decorticated specimen, X 1, paratype YPM 11952; 3, dorsal view, x 2, of the preceding specimen. [Skinner Ranch Formation (base), R. E. King locality 208 = USNM 705a.] Teguliferina boesei R. E. King: 4, 5, Dorsal and side views of a small specimen with flattened spines, X 1, hypotype USNM 154091b; 6, 7, anterior and dorsal views of another small specimen with both valves, X 1, hypotype USNM 154091a; 16, side of a specimen X 1, showing piled up rims (cone-in-cone structure), hypotype USNM 154091c [Neal Ranch Formation (upper 15 feet of bed 2 of P. B. King), USNM 701.] 8, 9, Dorsal view of an immature specimen, x 1, X 2, hypotype USNM 151346a; 10, 11, dorsal view of another immature individual, X 1, X 2, hypotype USNM 151346b; 12, 13 dorsal view of a half grown specimen, X 1, X 2, showing margin without protective spines, hypotype USNM 151346c; 14, two individuals attached to a Derbyia valve, X 1, hypotype USNM 154092b; 18, 19, side and ventral views of a specimen, preserving its flattened spines, X 1, hypo- type USNM 154092c; 20, 21, dorsal and ventral views of a specimen with marginal protective spines and flattened attachment spines, x 1, hypotype USNM 151347n; 22, dorsal view of a cluster having one specimen with well developed protective spines on the anterior side of the aperture, x 1, hypotype USNM 154092d; 23, a cluster of attached specimens, x 1, hypotype USNM 154092e; 24, side view of another cluster, X 1, hypotype USNM 154092f; 25, dorsal view of two specimens attached to a bryozoan, x 1, hypotype USNM 154092a. [Neal Ranch Formation (bed 4), USNM 701d.] 15, Side, showing the flattened attachment spines, X 1, hypotype USNM 154093a. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] 17, Dorsal view of a pedicle valve attached to Eolyttonia, X 1, hypotype USNM 154094a. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] Acritosia teguliferoides (R. E. King): 26, Cluster of small individuals, X 1, hypotype USNM 154058a; 27, interior of a pedicle valve, x 1, showing protruding ends of the rhizoid spines, hypotype USNM 154058-1; 28, fragmentary specimen, x 1, showing rhizoid spines, hypotype USNM 154058b; 29, 30, interior, x 1, X 2, showing the brachial valve and its cardinal process, hypotype USNM 154058c; 31, 32, another brachial valve and part of pedicle valve, X 1, X 2, showing endospines, hypotype USNM 154058d; 33, broken pedicle valve, X 2, showing brachial valve in position, hypotype USNM 154058g; 34, immature specimen in dorsal view, X 1, showing granulose exterior of brachial valve, hypotype USNM 154058m; 35, 36, interior of the pedicle valve, X 1, X 2, showing adductor track and internal spine bases, hypotype USNM 154058f; 37, 38, anterior view of a broken pedicle valve showing the dorsal valve in place, X 1, X 2, hypotype USNM 154058e; 39, interior of a pedicle valve, x 2, showing the proximal ends of the rhizoid spines, hypotype USNM 154058h; 40, Elliottella pedicle valve occupied by the young of Acritosia teguliferoides, x 2, hypotype USNM 154058L [Bone Spring Formation, USNM 728e.] NUMBER 19 1323 PLATE 203.- Acritosia and Teguliferina 1324 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 204 Teguliferina Teguliferina boesei R. E. King: 1-3, Interior and side, X 2, and exterior, X 1, views of a brachial valve, hypotype USNM 154095a; 14-16, interior, x 2, posterior, x 3, and side, X 2, views of another brachial valve, showing erect cardinal process, hypotype USNM 154095b. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 712w.] Broken specimen showing brachial valve in place, X 2, hypotype USNM 154110; 12, 13, anterior and ventral views of a pedicle valve, X 1, showing webbed attachment spines, hypotype USNM 154091f; 17, 18, ventral and side views of a specimen, x 1, showing fine striae, hypotype USNM 154091c [Neal Ranch Formation (upper 15 feet of bed 2 of P. B. King), USNM 701.] 6, Dorsal, view, X 2, and anterior view, X 1, showing the brachial valve in place but no protective spines, hypotype USNM 151352e; 7, 8, anterior view, X 1, dorsal view, X 2, of another specimen, showing the brachial valve in place but no protective spines yet developed, hypotype USNM 151352d; 9-11, dorsal, side, and anterior views of an adult with webbed spines and short protective spines, X 1, hypotype USNM 154093b; 19-21, anterior, X 2, dorsal, X 1, and anterior, X 1, views, showing the large webbed, rhizoid spines, hypotype USNM 154093c; 27, dorsal view of a small, cylindrical individual with long protective spines, X 1, hypotype USNM 154093d; 28, 29, dorsal and ventral views of a small cluster showing brachial valve in place and mat of attachment spines, X 1, hypotype USNM 154093L [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] 22, 23, Limbella with three attached Teguliferina, X 1, hypotype USNM 154094c [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] 24-26, Ventral and side views, X 1, and ventral view X 2, of two attached specimens, showing the webbed attachment spines binding them together, hypotype USNM 154092g; 30, dorsal view of a small cluster of attached specimens, x 1, hypotype USNM 154092h. [Neal Ranch Formation (bed 4), USNM 701d.] NUMBER 19 1325 PLATE 204.-Teguliferina 1326 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 205 Teguliferina Teguliferina conida (Stehli): 1-4, Dorsal, side, anterior, and ventral views, X 1, of a specimen with both valves, hypotype USNM 154097c; 5-8, ventral, dorsal, side, and anterior views, X 1, showing bases of webbed rhizoid spines, hypotype USNM 154097b; 9-12, side, anterior, ventral, and dorsal views of a complete specimen, showing brachial valve in feeding (?) position, webbed spines and protective spines, hypotype USNM 154097a; 13-16, dorsal, ventral, anterior, and side views of a complete specimen, X 1, hypotype USNM 154097d; 17, anterior view of the preceding specimen, x 2, showing the webbed, rhizoid spines. [Bone Spring Formation, AMNH 625.] 18-21, Ventral, side, anterior, and dorsal views of a young individual, X 1, hypotype USNM 154096a; 22-24, side and anterior views, X 1, and side view, X 2, showing webbed spines on a small adult, hypotype USNM 154096b; 25, 26, side and anterior views, X 1, of a small specimen, hypotype USNM 154096c; 27, anterior view, X 2, of the preceding specimen, showing the webbed, rhizoid spines; 28, large adult attached to a small coral colony, X 1, hypotype USNM 154096m; 29-31, dorsal, ventral, and anterior views of a young individual with webbed spines, X 1, hypotype USNM 154096d; 32, ventral view of the preceding specimen, x 2, showing the webbed rhizoid spines; 33, dorsal view of an immature specimen, X 1, hypotype USNM 154096f; 34, 35, interior of a broken specimen, x 1, X 2, showing the brachial valve in place, hypotype USNM 154096e. [Bone Spring Formation, USNM 728e.] NUMBER 19 1327 PLATE 205.-Teguliferina 1328 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 206 Teguliferina Teguliferina conida (Stehli): 1, 2, Anterior and dorsal views of a young pedicle valve, X 1, hypotype USNM 154098a. [Bone Spring Formation, 728f.] 8, Dorsal view, x 1, of a young specimen with both valves but not yet having developed pro- tective spines, hypotype USNM 154096J; 24-26, interior, X 1, interior and side, X 2, of a brachial valve, showing erect cardinal process and endospines, hypotype USNM 154099a; 27-29, interior, X 1, and side and interior, X 2, of another brachial valve, showing erect cardinal process, hypotype USNM 154099b; 30-32, interior, x 1, and interior and side, X 2, of a wide brachial valve, showing cardinal process and breviseptum, hypotype USNM 154099c; 33-36, anterior, side, dorsal, and pos- terior views of a large specimen, x 1, hypotype USNM 154096g; 37, ventral view of the preceding hypotype, X 2, showing webbed attachment spines; 38, 39, dorsal and anterior views of a pedicle valve, showing the webbed spines, X I, hypotype USNM 154096h; 40, 41, dorsal and side views of another pedicle valve, X 1, showing the webbed rhizoid spines, hypotype USNM 154096-1. [Bone Spring Formation, USNM 728e.] 3-6, Dorsal, ventral, anterior, and side views of a young specimen, X 1, hypotype USNM 151375i; 7, dorsal view of a specimen distorted by crowding, X 1, hypotype USNM 151375c; 9-12, dorsal, ventral, side, and anterior views of a complete specimen, X 1, hypotype USNM 151375e; 13, anterior of the preceding specimen, x 2, showing the webbed rhizoid spines; 14-17, dorsal, an- terior, side, and ventral views of a specimen stripped of its spines, X 1, hypotype USNM 151375d; 18, 19, dorsal and side views of a large pedicle valve, X 1, hypotype USNM 151375a; 20, exterior of a brachial valve, X 1, hypotype USNM 151375J; 21-23, posterior view, X 3, and interior and side views, X 2, of the preceding specimen, showing cardinal process, breviseptum and endospines. [Skinner Ranch Formation (base), USNM 705a.] 42, 43, Dorsal view of a complete specimen, x 1, X 2, showing granulose surface and long protective spines, hypotype USNM 123889. [Bone Spring Formation, AMNH 625.] NUMBER 19 1329 PLATE 206.-Teguliferina 24 ^?mñ ?' i 2 3 A- - 94k. 'L \ li\ wm '^SSS"' 42 ?ø IS in -, 1330 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 207 Teguliferina Teguliferina compacta, new species: 1-3, Dorsal, anterior, and ventral views of a specimen, X I, showing the protective spines, holotype USNM 151370a; 4-6, anterior, dorsal, and ventral views of a wide specimen, X 1, paratype USNM 151370c; 7-9, dorsal, anterior, and ventral views of another paratype, USNM 151370b. [Skinner Ranch Formation (top), USNM 705r.] 10, Anterior view of a specimen, x 2, showing remnants of the webbed attachment spines, para- type USNM 151369a. [Hess Formation (Taylor Ranch Member), USNM 702d.] Teguliferina parva, new species: 11, 12, Anterior and side views of two large pedicle valves, X 1, paratype USNM 151372a, b; 13, 14, anterior and dorsal views, X 1, of a depressed specimen, paratype USNM 151372f; 15, 16, anterior and dorsal views of another complete specimen, X 1, holotype USNM 151372e; 17, 18, ventral view of a broken specimen, x 1, X 2, showing the brachial valve, paratype USNM 151372c [Red Eagle Formation, USNM 761.] Teguliferina solidispinosa, new species: 19-21, Anterior, side, and posterior views of a pedicle valve, X 1, showing tiered marginal flanges (cone-in-cone structure) and webbed spines, X 1, paratype USNM 154100b; 22, side view of the preceding specimen, X 2, showing the webbed, rhizoid spines; 23-25, posterior, anterior and dorsal views, X 1, of a pedicle valve, showing the strong protective spines, paratypes USNM 154100c; 26, 27, anterior and side views of another pedicle valve, X 1, showing the protective spines over the aperture and webbed, rhizoid spines, holotype USNM 154100a. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] Teguliferina boesei R. E. King: 28, 29, interior of two brachial valves, X 2, showing large, erect cardinal process, hypotypes USNM 154101b, c; 30, interior of another brachial valve, X 2, showing a few aborted endospines, hypotype USNM 154101a. [Neal Ranch Formation (bed 4). USNM 701d.] 31, Exterior of a large brachial valve, x 1, hypotype USNM 154091h; 32, 33, interior and side views of the preceding specimen, X 2; 34, posterior of the preceding specimen, X 4, showing the myophore; 35, 36, interior and side views of another brachial valve, X 2, hypotype USNM 154091g; 37, posterior view of the preceding specimen, x 4, showing its myophore; 38, cluster of specimens, X 1, hypotype USNM 15409H. [Neal Ranch Formation (bed 2 of P. B. King), USNM 701.] NUMBER 19 1331 PLATE 207.-Teguliferina V*mufo, 'fr ^ IPi ^^, 16 - -. ,- - i 13 14 B 12 17 1332 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 208 Paucispinifera, Liosotella, Glyptosteges, Cooperina, and Horridonia Paucispinifera magnispina, new species: 1-4, Dorsal, posterior, ventral, and side views of a complete specimen, X 1, paratype USNM 149562a. [Word Formation (Willis Ranch Member), USNM 706e.] Liosotella texana (Girty): 5-8, Posterior, dorsal, ventral, and side views, X 1, of the holotype USNM 118526a. [Delaware Mountain Formation, USGS 2903 (green).] Glyptosteges angustus (R. E. King): 9-12, Anterior, side, posterior, and ventral views, X 1, of the lectotypc YPM 11807a. [Skinner Ranch Formation, R. E. King locality 4.] Cooperina parva, new species: 13, 14, An attached pedicle valve, X 1, X 2, paratype USNM 154174; 20-25, posterior, dorsal, side, anterior, and ventral views of a complete specimen, X 8, holotype USNM 152638a; 33-35, exterior, interior, and anterior views of a brachial valve, X 8, paratype USNM 152638b; 36, 37, interior and exterior of another brachial valve, x 8, showing adductor platforms, paratype USNM 152638c [Road Canyon Formation (base), USNM 702c] 15, 16, Interior of an attached pedicle valve, X 1, X 2, paratype USNM 154175a. [Cathedral Mountain Formation (Wedin Member), USNM 700x.] 17-19, Anterior, dorsal, and posterior views of a complete specimen, X 8, paratype USNM 152639d; 26-30, anterior, posterior, side, ventral, and interior views of a pedicle valve, X 8, para- type USNM 152639e; 31, 32, ventral and dorsal views of a complete specimen, x 8, paratype USNM 152639f; 38, interior of a brachial valve, x 8, showing adductor platforms, paratype USNM 152639g (lost). [Hess Formation (Taylor Ranch Member), USNM 702d.] Horridonia texana R. E. King: 39-42, Side, dorsal, ventral, and posterior views of the holotype, X 1, YPM 11508. [Road Canyon Formation, R. E. King locality 255.] 43-46, Interior, side, posterior, and exterior views of a brachial valve, X 1, showing median fold, and ear spines, hypotype USNM 154176a; 47, myophore of the cardinal process, x 2, of the pre- ceding specimen. [Road Canyon Formation, USNM 735a.] NUMBER 19 1333 PLATE 208.-Paucispinifera, Liosotella, Glyptosteges, Cooperina, and Horridonia V' s* ~s fiffcilP. ' *-*? 1334 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 209 Cooperina Cooperina triangulata, new species: 1, 2, Ventral view of a specimen with umbonal region removed to show lobed cardinal process and adductor platforms, X 8, paratype USNM 152640e; 3-6, side, in- terior, exterior, and anterior views, X 8, of another brachial valve having a strongly lobate cardinal process, paratype USNM 152640g; 22-26, posterior, anterior, dorsal, side, and pedicle views, X 8, paratype USNM 152640d; 27-31, side, anterior, ventral, and posterior views of another complete specimen, x 8, holotype USNM 152640c; 36, 37, side views of two specimens attached to the pedicle valve of Diplanus, X 3, paratypes USNM 152640i, h. [Neal Ranch Formation (bed 4), USNM 701d.] 7-11, Anterior, exterior, interior, side, and oblique views, X 8, of a brachial valve, showing the lobate cardinal process and adductor platforms, paratype USNM 154138a; 12-16, exterior, side, oblique, interior, and anterior views of another, very attenuate brachial valve, x 8, paratype USNM 154138b. [Neal Ranch Formation (bed 4), USNM 721g.] 17-21, Side, dorsal, posterior, anterior, and ventral views of a complete specimen, x 8, paratype USNM 154139b; 32-35, exterior, oblique, interior, and anterior views of a brachial valve, X 8, showing prominent adductor platforms, paratype USNM 154139a. [Neal Ranch Formation (bed 9 of Cooper), USNM 701a3.] Cooperina subcuneata, new species: 38-40, Side, anterior, and interior views of an attached pedicle valve, X 3, paratype USNM 154140. [Road Canyon Formation, USNM 722e.] 41-45, Interior tilted, side, anterior, interior, and exterior views of a brachial valve, X 8, paratype USNM 154141, showing adductor platforms. [Road Canyon Formation, USNM 720d.] 46-50, Ventral, posterior, side, anterior, and dorsal views of a complete specimen, X 8, holotype USNM 151241a; 51, 52, piece of shell occupied by four pedicle valves, X 1, X 3, paratype USNM 151241c; 58, 59, dorsal and side views of a complete, attached specimen, x 8, paratype USNM 151241b. [Road Canyon Formation, USNM 721j.] 53-57, Dorsal, anterior, posterior, ventral, and side views of a complete specimen, x 8, para- type USNM 152641a. [Road Canyon Formation, USNM 726d.] NUMBER 19 1335 PLATE 209. -Cooperina 1336 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 210 Cooperina Cooperina inexpectata, Termier, Termier, and Pajaud: 1, Dorsal view of four hypotypes, X 1, USNM 153198k, a, j, c (see figures 11-14, 42-45, and 55, 56, below); 4, 5, dorsal and ventral views of a complete specimen with aureole of rhizoid spines, and huge cicatrix, x 6, hypotype USNM 153198e; 6, 7, another pedicle valve in interior view, x 6, showing aureole of attachment spines and huge cicatrix, hypotype USNM 153198f; 8, 9, ventral view, x 6, showing spines on exterior, and interior view, x 3, hypotype USNM 153198g; 10, interior of a pedicle valve, X 3, showing median ridge, hypotype USNM 153198h; 11-14, side, posterior, anterior, and interior views, X 6, of a pedicle valve, showing cicatrix and median ridge, hypotype USNM 153198J; 15, fragment of pectenoid shell occupied by a specimen of Cooperina, X 2, hypotype USNM 154142f (see plate 212: figure 16, for natural size view); 16-18, side, ventral, and dorsal views of a complete specimen, X 6, hypotype USNM 152637d; 19, interior of a brachial valve, x 6, showing large, lobed cardinal process and adductor platforms, hypotype USNM 153198-1; 20-24, anterior, exterior, posterior, side, and interior views of a brachial valve, X 6, showing median elevation, lobate cardinal process and adductor platforms, hypotype USNM 153198m; 25-29, anterior and posterior, exterior, interior and side views of a long slender individual, x 6, having well defined brachial ridges, hypotype USNM 153198b; 30-34, anterior and posterior, interior, side, and exterior views of a small speci- men, x 6, showing adductor platforms, hypotype USNM 153198n; 35-39, posterior, anterior, interior, side, and exterior views of a brachial valve, X 6, showing spines on exterior, adductor platforms and typically productid cardinal process, hypotype USNM 153198c!; 40, six brachial valve interiors, x 1, hypotypes USNM 153198b (for enlarged views, see figures 25-29, 30-34, 35-39, 20-24, 19); 42^45, ventral, interior, side and anterior views of a spiny pedicle valve, X 6, showing broad interarea; hypotype USNM 153198c; 46-49, anterior, ventral, side, and interior views of a pedicle valve, X 6, showing large cicatrix of attachment and rhizoid spines, hypotype USNM 153198a; 50, exterior of a pedicle valve, x 6, showing the numerous ornament spines, hypotype USNM 153198p; 55, 56, ventral and dorsal views of a complete attached specimen, X 6, hypotype USNM 153198k; 57-60, dorsal, side, ventral, and anterior views of a specimen stripped of its spines, X 6, hypotype USNM 152637g; 61, interior of a pedicle valve, x 6, showing anterior end of the median ridge, hypotype USNM 153198L [Word Formation (Willis Ranch Member), USNM 706e.] 2, 3, Small leptodid, x 1, X 2, showing several attached individuals, hypotype USNM 154143a; 41, interior of a brachial valve, x 3, hypotype USNM 154143b; 51, 52, ventral and interior views of a pedicle valve, x 3, hypotype USNM 154153d: 53, 54, ventral and dorsal views of a complete specimen, X 3, hypotype USNM 154143c [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1337 PLATE 210,-Cooperina 1338 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 211 Atelestegastus Atelestegastus marginatus, new species: 1-3, Interior, side, and exterior views, X 6, of a brachial valve, showing lobate cardinal process, paratype USNM 154135a; 8-10, interior, exterior, and posterior, X 6, of another brachial valve, paratype USNM 154135b; 27-31, posterior, anterior, dorsal, ventral, and side views of a large complete specimen, x 6, holotype USNM 154135c [Neal Ranch Formation (bed 4), USNM 721g.] 4-7, Side, exterior, interior, and posterodorsal views, x 6, of => brachial valve having a lobate cardinal process, USNM 150877f; 11, posterior of a brachial valve, X 6, showing a poorly lobed cardinal process, paratype USNM 150877-1; 12-16, dorsal, anterior, posterior, ventral, and side views of a complete specimen, preserving some of its body spines, X 6, paratype USNM 150877g; 17-20, dorsal, ventral, posterior, and side views of a complete specimen, X 6, paratype USNM 150877h; 21-24, posterior, anterior, and ventral views, X 6, of a pedicle valve, paratype USNM 150877i; 25, 26, exterior and interior of a brachial valve with lobate cardinal process, X 6, para- type USNM 150877j; 32-35, side, dorsal, ventral, and posterior views of a complete specimen, X 6, paratype USNM 150877b; 37, posterior of a pedicle valve, x 6, showing rhizoid spines, and inter- area, paratype USNM 150877k; 51, dorsal view of two complete specimens, X 1, paratypes USNM 150877g, h. [Neal Ranch Formation (bed 4), USNM 701d.] 36, Interior of the pedicle valve of Geyerella occupied by several specimens of Atelestegastus, X 1, paratype USNM 154136; 38, brachial valve of Derbyia with Atelestegastus attached, X 1, paratype USNM 150878a; 39, 40, pedicle valve of young Meekella occupied by Atelestegastus, X 1, X 2, paratype USNM 150878b. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701h.] 41, Exterior of the brachial valve of Limbella with attached Atelestegastus, X 1, paratype USNM 154137a; 47-50, anterior, posterior, ventral, and dorsal views of a complete specimen, X 6, paratype USNM 154137b. [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] 42-46, Interior, anterior, posterior, ventral, and side views of a pedicle valve, x 6, paratype USNM 150875. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] NUMBER 19 1339 PLATE 211.-4 telestegastus 1340 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 212 Chonosteges and Cooperina Chonosteges variabilis, new species: 1, 2, Interior of a brachial valve, X 3, X 4, showing cardinal process in the immature stage, paratype USNM 154162c; 3, immature brachial valve, X 3, show- ing open V-shaped cardinal process, paratype USNM 154162a; 4, interior of a misshapen brachial valve, the victim of crowding, X 3, showing an obese cardinal process, paratype USNM 154162b. [Cathedral Mountain Formation, USNM 702.] 5, Posterodorsal view of a brachial valve, X 3, showing the myophore, paratype USNM 154154d; myophore of an obese specimen, X 3, showing extreme lobation, paratype USNM 154154e; anterior of a brachial valve showing needles (above) that form a strainer device, X 3, paratype USNM 123903b; 8, another view of a brachial value showing inlet spines on anterior margin, X 3, paratype USNM 123903a; 9, anterior -of another brachial valve, X 4, showing the needle-like strainers and the anterior flange, paratype USNM 123903d; 10, interior of the preceding brachial valve, X 3, showing overgrown cardinal process, strongly entrenched adductor scars and brachial ridges. [Cathedral Mountain Formation, USNM 702un.] Cooperina inexpectata Termier, Termier, and Pajaud: 11, Echinosteges with brachial valve over- loaded with epifauna consisting of Cyclacantharia and Cooperina, X 1, hypotype USNM 153185a; detail of the preceding specimen, x 2, showing Cooperina with its hairlike ornament spines; two attached tetracorals with Cooperina occupying the angle between them, X 1, hypotype USNM 154142b; 14, 15, brachial valve of Echinauris occupied by four individuals, X 1, X 2, showing erect mode of attachment, hypotype USNM 154142e; 16, fragment of pectenoid shell, X 1, with attached Cooperina, hypotype USNM 154142f; 17, 18, Grandaurispina, xl, X 2, with attached Cooperina, hypotype USNM 154142h; 19, Cooperina in a secluded niche between two Cyclacantharia valves, X 2, hypotype USNM 154142a; 20, fragment of a Derbyia valve with several attached individuals of Cooperina, X 1, hypotype USNM 153184; 21, 22, Cooperina occupying the brachial valve of a Cyclacantharia, x 1, X 2, hypotype USNM 153185b. [Word Formation (Willis Ranch Member), USNM 706e.] NUMBER 19 1341 PLATE 212.-Chonosteges and Cooperina 1342 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 213 Limbella Limbella wolfcampensis (R. E. King): 1, Ventral view of a fragmentary pedicle valve, X 1, para- lectotype YPM 11849. [Lenox Hills Formation, R. E. King locality 193.] 2-5, Anterior, side, ventral and posterior views of another fragmentary pedicle valve, X 1, paralectotype YPM 11839. [Gaptank Formation (Uddenites-bearing Shale Member), R. E. King locality 88s.] Interior of a fragmentary brachial valve, X 1, showing the cardinal process, lectotype YPM 11847a. [Neal Ranch Formation (bed 9 of R. E. King), R. E. King locality 93.] Interior of a young brachial valve, X 1, hypotype USNM 149061a; 8-10, ventral view of three immature pedicle valves, X 1, hypotypes USNM 149061c, d, b; 15-17, ventral view, of three more half-grown pedicle valves, X 1, showing rhizoid and ornament spines, hypotype USNM 149061 f, j, h; 20-22, ventral, dorsal, and side views of a young but complete specimen, X 1, hypotype USNM 149061g; 25-27, dorsal, ventral, and side views of a young adult, x 1, hypotype USNM 14906H; 28, 29, dorsal and ventral views of an adult, x 1, showing scaly pedicle valve and fragments of the flange, hypotype USNM 149061c [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] 11-14, Side, posterior, exterior, and interior views, X 1, of a brachial valve, hypotype USNM 154206; 23, 24, side and dorsal views of a complete young specimen, x 1, hypotype USNM 149052d; 18, 19, dorsal and ventral views of a complete specimen, x 1, showing marginal flange and long ornament spines, hypotype USNM 154207. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] NUMBER 19 1343 PLATE 21B.-Limbella 1344 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 214 Limbella Limbella wolfcampensis (R. E. King): 1-4, Anterior, dorsal, ventral, and side views of a complete specimen with large flange, X 1, hypotype USNM 154203; 11, exterior of an old ventral valve, X 1, showing scaly surface, hypotype USNM 154199. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] Dorsal view of a complete specimen with flange, x 1, hypotype USNM 154204. [Neal Ranch Formation (bed 4), USNM 701-1.] Interior of a pedicle valve, x 1, showing muscle scars, hypotype USNM 124120d; 12, 13, posterior and interior, X 4, showing cardinal process, narrowly lobed and small adductor scars, hypotype USNM 124120g; 14, ventral view of a young pedicle valve, x 1, showing incipient geniculation and long ornament spines, hypotype USNM 124120c [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] 7-10, Posterodorsal, posterior, and exterior views of a pedicle valve, X 1, showing the cardinal process, hypotype USNM 154205; 15-18, anterior, ventral, side, and dorsal views, X 1, of a com- plete specimen with flange and scaly pedicle valve, hypotype USNM 149049b; 19-21, dorsal, ventral, and side views, X 1, showing marginal flange, rhizoid spines, scaly exterior of the pedicle valve and ornament spines, hypotype USNM 149049c [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701h.] NUMBER 19 1345 PLATE 2U.-Limbella L>^> j- 1346 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 215 Limbella Limbella wolfcampensis (R. E. King): 1-3, Ventral, side, and dorsal views, x 1, of a large complete individual on which is perched a specimen of Diplanus, hypotype USNM 149053a. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] Limbella victorioensis Stehli: 4-6, Ventral view of three immature specimens, X 1, hypotypes USNM 154200a-c; 7-9, posterior, ventral, and interior views of a young adult, x 1, hypotype USNM 154200d; 10-12, interior, side, and ventral views of a young pedicle valve, x 1, having a strong development of rhizoid spines, hypotype USNM 154200e; 13-16, exterior, posterior, side, and interior views, X 1, of a brachial valve, hypotype USNM 154200f; 17-19, side, ventral and interior views of a large adult having a marginal flange and showing the muscle scars, X 1, hypotype USNM 152648a; 20-24, anterior, ventral, posterior, and interior views, X 1, of a large pedicle valve having a strong marginal flange, hypotype USNM 152648b; 25-27, anterior, ventral, and interior views of a small adult pedicle valve, X 1, showing a flange and muscle scars, hypotype USNM 152648c [Bone Spring Formation, USNM 728f.] NUMBER 19 1347 PLATE 215,-Limbella 1348 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 216 Limbella Limbella victorioensis Stehli: 1-4, Exterior, interior, posterior, and side views of a brachial valve, X 1, showing brachial ridges, adductor platforms, and lateral ridges, hypotype USNM 154200h; 5-8, posterior, exterior, interior, and side views of another brachial valve, X 1, hypotype USNM 154200g; 9, 10, interior and ventral views of a large pedicle valve, X 1, showing a marginal flange and ornament spines, hypotype USNM 154200L [Bone Spring Formation, USNM 728f.] Limbella wolfcampensis (R. E. King): 11-13, Ventral, posterior, and side views of a large pedicle valve, X 1, hypotype 154201. [Lenox Hills Formation, USNM 705k.] 15, Dorsal view of a complete specimen, X 1, showing marginal flange and rhizoid spines, hypotype USNM 124120a. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] Limbella species 1: 14, Ventral view of a pedicle valve, X 1, figured specimen USNM 152647. [Hess Formation (Taylor Ranch Member), USNM 713x.] Limbella costellata, new species: 16-18, Side, ventral, and posterior views of a pedicle valve, X 1, holotype USNM 149086a; 19, Dorsal view of a small, complete specimen, X 1, paratype USNM 149086b. [Gaptank Formation, USNM 700g.] 20-23, Ventral, dorsal exterior, side, and dorsal views of a complete specimen, x 1, paratype USNM 154202. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 702n.] NUMBER 19 1349 PLATE 216.-Limbella r ' Hiia.1&*4mi> k 1350 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 217 Paucispinifera, Cyclacantharia, Limbella, and Rhamnaria Paucispinifera latidorsata (Girty): 1-3, Dorsal, interior, and posterior views of a fragmentary brachial valve, x 2, showing the cardinal process, zygidium, and brachial ridges, hypotype USNM 153952c [Bell Canyon Formation (Hegler Member), USNM 731.] Cyclacantharia kingorum, Cooper and Grant: 4, Interior of the brachial valve, X 6, showing the cardinal process and the chilidium covering it, hypotype USNM 124140d. [Word Formation (Willis Ranch Member), USNM 706e.] Limbella limbata, new species: 5-8, Interior, side, posterior, and exterior of a brachial valve, X 1, paratype USNM 154208c; 9, 10, anterior and ventral views of a pedicle valve, X 1, showing the marginal flange and rhizoid spines, paratype USNM 154208b; 11, 12, anterior and ventral views of another large pedicle valve, X 1, showing the flange and fine radial ornament, holotype USNM 154208a; 13, 14, ventral view of an immature specimen, X 1, X 3, preserving the initial attach- ment ring, paratype USNM 154208c [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] 15-17, Anterior, ventral, and interior views of a pedicle valve, with marginal flange, and showing muscle scars, x 1, paratype USNM 149075. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707d.] Rhamnaria grandis, new species: 18-21, Ventral, posterior, anterior, and side views, X 1, of para- type YPM 11613. [Cathedral Mountain Formation, R. E. King locality 15.] NUMBER 19 1351 PLATE 217.-Paucispinifera, Cyclacantharia, Limbella, and Rhamnaria 1352 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 218 Edriosteges Edriosteges multispinosus Muir-Wood and Cooper: 1, 2, Ventral and dorsal views of a complete specimen, x 1, having a very long marginal flange, hypotype USNM 149122d; 4, large Meekella with attached Edriosteges, x 1, hypotype USNM 154189a; 7- 9, side, dorsal, and ventral views of a young complete specimen, x 1, hypotype USNM 154184p; 10, ventral view, X 1, of an attached young specimen, hypotype USNM 154189b; 11, dorsal view of a specimen with long marginal flange and rhizoid spines, much overgrown by epifauna, x 1, hypotype USNM 154189c [Road Canyon Formation (base), USNM 702c] 3, Immature specimen with initial attachment ring and earliest ornament spines, X 4, hypotype USNM 154188b; 5, 6, dorsal views, x 1, of two specimens distorted by crowding, hypotypes USNM 154183b, d. [Road Canyon Formation (base), USNM 703a.] Edriosteges beedei (R. E. King): 12-14, Dorsal view, x 1, and dorsal and ventral views, X 2, of a specimen distorted by crowding, hypotype USNM 149119; 15, 16, interior of the ventral and brachial valves of the preceding specimen, x 2; 17, the myophore of the cardinal process of the preceding specimen, x 3; 18-20, side, ventral, and dorsal views of a complete specimen, x 1, hypotype USNM 149120. [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1353 PLATE 21&.-Edriosteges 1354 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 219 Edriosteges Edriosteges multispinosus Muir-Wood and Cooper: 1, 2, Ventral and dorsal views of a large indi- vidual with long marginal flange and long rhizoid spines, X I, hypotype USNM 149115a; 4, ventral view of a young pedicle valve, x 1, hypotype USNM 154183m; 6, ventral view of another young pedicle valve with slender rhizoid spines, X 1, hypotype USNM 154185c; 12, ventral view of an immature pedicle valve, X 1, hypotype USNM 154185b; 13, another young pedicle valve with long rhizoid spines, x 1, hypotype USNM 154183s; 19, an immature pedicle valve with long rhizoid spines, X 1, hypotype USNM 154185a; 20, immature pedicle valve with most of its urn- bonal region cemented to its substrate, X 1, hypotype USNM 154185e; 22, an immature pedicle valve, X 1, hypotype USNM 154185f: 25, an immature pedicle valve with long ornament spines, X 1, hypotype USNM 154185d: 26, 27, dorsal views of two individuals with exceptionally long rhizoid spines, X 1, hypotypes USNM 149115b, c. [Road Canyon Formation (base), USNM 703a.] 3, Ventral view of a young pedicle valve, x 1, hypotype USNM 154184a; 5, ventral view of an immature pedicle valve with long ornament spines, x 1, hypotype USNM 154184g; 7-9, ventral views of immature pedicle valves with rhizoid and ornament spines, X 1, hypotypes USNM 154184q, h, c; 10, 11, dorsal and ventral views of an immature specimen distorted by crowding, X 1, hypotype USNM 154184e; 14-16, immature pedicle valves, x 1, hypotypes USNM 154184b, k, f; 17, 18, interior of an immature pedicle valve, x 2, X 1, showing use of rhizoid spines, hypotype USNM 154184d; 21, 23, 24, ventral view of two immature pedicle valves, X 1, showing attachment surfaces and rhizoid spines hypotypes USNM 154184i, m, 1. [Road Canyon Formation (base), USNM 702c] NUMBER 19 1355 PLATE 2l9.-Edriosteges 1356 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 220 Edriosteges Edriosteges multispinosus Muir-Wood and Cooper: 1-4, 29, Ventral, side, dorsal, anterior, and posterior views, x 1, of a small complete specimen without its spines, hypotype USNM 154183t; 5, interior of the brachial valve of the preceding specimen, x 1, showing a normal cardinal pro- cess; 6, 7, dorsal and ventral views of another complete specimen, x 1, showing ornament spines on the pedicle valve but a naked brachial valve, hypotype USNM 154187; 8-10, side, posterior, and interior views of the brachial valve of the preceding specimen, x 1; 11-14, posterior, interior, side, and exterior views of a medium-sized brachial valve with normal cardinal process, X 1, hypotype USNM 154183f; 15-18, posterior, side, exterior, and interior views of an obese brachial valve, X 1, hypotype USNM 154183i; 19, myophore of the preceding specimen, x 2; 20, posterior part of a small obese brachial valve having a greatly thickened cardinal process, X 1, hypotype USNM 154183u; 21-24, exterior, side, posterior, and interior views of a young brachial valve having a cardinal process with juvenile characters, X 1, hypotype USNM 154183J; 25-28, side, exterior, posterior, and interior of a brachial valve with moderately developed cardinal process, X 1, hypotype USNM 154183g; 30, interior of a young brachial valve, x 1, hypotype USNM 154183v; 31, 32, side and interior views of an old brachial valve with greatly thickened and lobate cardinal process, X 2, hypotype USNM 154183w. [Road Canyon Formation (base), USNM 703a.] NUMBER 19 1357 PLATE 220.-Edriosteges 1358 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 221 Edriosteges Edriosteges multispinosus Muir-Wood and Cooper: 1, 2, Ventral view of two immature specimens, X 1, hypotypes USNM 154183p, q; 3, 4, exterior and interior of a young pedicle valve, X 1, hypotype USNM 154183n; 5-7, ventral, side, and dorsal views of a large adult with well developed marginal flange and numerous rhizoid spines, x 1, paratype USNM 123906b; 8, 9, dorsal and ventral views of a young specimen with the brachial valve in place, X 1, hypotype USNM 154183b; 10, 18, ventral and interior views of an immature pedicle valve, X 1, hypotype USNM 154183r; 11-14, anterior, dorsal, ventral, and side views, X 1, of the holotype USNM 123906a; 15, interior of the pedicle valve of the holotype, X 1, showing muscle scars; 16, 17, interior of the brachial valve of the holotype, x 1, X 2, showing adult cardinal process, muscle scars and bra- chial ridges; 19, interior of another immature pedicle valve, x 1, hypotype USNM 154183p (for exterior view see figure 1); 20-23, exterior, side, and interior views of an immature brachial valve, X 1, hypotype USNM 154183k. [Road Canyon Formation (base), USNM 703a.] NUMBER 19 1359 PLATE 22\.-Edriosteges 1360 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 222 Edriosteges Edriosteges tenuispinosus, new species: 1-5, Anterior, posterior, side, dorsal, and ventral views of a complete specimen, x 1, holotype USNM 152650. [Cathedral Mountain Formation, USNM 703a1.] Edriosteges multispinosus Muir-Wood and Cooper: 6, 7, Side and dorsal views of a complete speci- men, x 1, showing a marginal flange, hypotype USNM 149121; 8, Detail of the ornament, X 3, of the preceding specimen. [Road Canyon Formation (base), USNM 702c] 9-11, Side, dorsal, and ventral views of a complete specimen with marginal flange and rhizoid spines, X 1, paratype USNM 123907; 12, interior of the brachial valve of the preceding specimen, X 1, showing lobate cardinal process, thick adductor callosities and thick marginal rim; 13, ventral view of an immature pedicle valve, x 4, showing ornament and rhizoid spines, paratype USNM 123906c [Road Canyon Formation (base), USNM 703a.] NUMBER 19 1361 PLATE 222-Edriosteges ftj$&&ffiKZ&'ii k'"''X 1362 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 223 Edriosteges and Echinosteges Edriosteges compactus, new species: 1-4, Ventral anterior, posterior, and dorsal views of a complete specimen burdened by tetracorals, X 1, paratype USNM 149137c [Road Canyon Formation, USNM 709c] 5-9, Posterior, dorsal, ventral, anterior, and side views of the holotype, X 1, USNM 152651a; 10-14, anterior, dorsal, posterior, ventral, and side views of another complete specimen, X 1, paratype USNM 152651c [Road Canyon Formation, USNM 721t.] 15, 16, Posterior and interior views of the brachial valve interior, X 1, paratype USNM 149140c [Road Canyon Formation, USNM 710u.] Edriosteges multispinosus Muir-Wood and Cooper: 17, 18, Interior of the brachial and pedicle valves of the same specimen an obese form, x 1, showing strongly lobed cardinal process and thickened muscle regions, hypotype USNM 154188a. [Road Canyon Formation (base), USNM 703a.] Edriosteges beedei (R. E. King): 19-22, Ventral, and side views, X 1, and ventral and dorsal views, X 2, of a complete specimen referable to Edriosteges, lectotype YPM 11876a. [Cathedral Mountain Formation, R. E. King locality 123.] Echinosteges tuberculatus (R. E. King): 23, 24, Interior, X 1, X 2, of a brachial valve referable to this species, former paratype TI1045. [Word Formation (Willis Ranch Member), R. E. King locality Tx.] NUMBER 19 1363 PLATE 223.-Edriosteges and Echinosteges 3 1364 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 224 Echinosteges Echinosteges tuberculatus (R. E. King): 1, Two pedicle valves with rhizoid spines entwined for attachment, x 1, hypotype USNM 149039a; 2-4, interior and interior tilted posteriorly, x 2, and interior X 1, of an elongated brachial valve, showing adductor platforms and scars, and a juvenile cardinal process, hypotype USNM 123905b; 5, exterior of a pedicle valve, x 1, showing anterior flange, hypotype USNM 123453k; 6, dorsal view of a specimen with the brachial valve in place, X 1, hypotype USNM 123905i, 7, exterior of a fragmentary brachial valve, x 1, showing long spines on the brachial valve, hypotype USNM 149019a; 8, ventral view of an attached specimen, X 1, showing the mass of rhizoid spines used in fixation, hypotype USNM 123905k; 9, interarea showing spines emerging from the elytridium, x 2, hypotype USNM 149039b. [Word Formation (Willis Ranch Member), USNM 706c] 10, Side view of an attached specimen, x 1, showing direction of rhizoid spines, hypotype USNM 154177a. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1365 PLATE 224.-Echinosteges 1366 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 225 Echinosteges Echinosteges tuberculatum (R. E. King): 1-3, Interior, ventral, and side views of a pedicle valve, X 1, showing marginal flange, interarea, and rhizoid spines, hypotype USNM 149019b; 5, exterior of a pedicle valve with well preserved ornament spines, X 1, hypotype USNM 124453c; 6, exterior of the preceding specimen, x 2, showing details of the spiny surface; 7, interarea of an elongated specimen, X 2, showing exceptional development of the elytridium, hypotype USNM 123905a; 8- 10, ventral, side, and interior views of a young pedicle valve, x 1, hypotype USNM 154178a; 11, 12, interior and exterior of another but younger specimen than the preceding, X 1, hypotype USNM 154178b; 13, 14, interior and exterior of a greatly elongated pedicle valve having a much exaggerated interarea probably induced by crowding, x 1, hypotype USNM 154178c; 15, 16, exterior and interior of a young pedicle valve, x 1, hypotype USNM 154178d. [Word Formation (Willis Ranch Member), USNM 706c] 4, Specimen with umbonal region stripped away to show cardinal process and adductor plat- forms, X 1, hypotype USNM 154177. [Word Formation (China Tank Member) USNM 706c] 17-19, Side, ventral, and dorsal views of a complete specimen with most of the brush of rhizoid spines retained, x 1, hypotype USNM 149024a. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1367 PLATE 225.-Echinosteges +&+$##& 10 1368 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 226 Echinosteges Echinosteges tuberculatus (R. E. King): 1-3, Interior of the brachial valve, complete specimen with brachial valve in place and interior of the pedicle valve, showing all generic details to perfection, x 1, hypotype USNM 149026. [Word Formation (China Tank Member), USNM 706c] 4, Interior of an imperfect pedicle valve, X 1, showing the thick adductor callosity and flabellate diductor scars, hypotype USNM 123453m; 5, interior of another pedicle valve, X 1, showing broad interarea, narrow elytridium, and anterior end of adductor callosity, hypotype USNM 123453a; 11, interior of a young pedicle valve, X 1, showing narrow adductor callosity, hypotype USNM 149019c; 18, interarea and rhizoid spines of an adult pedicle valve, X 2, hypotype USNM 123452. [Word Formation (Willis Ranch Member), USNM 706c] 6-8, Posterior, interior, and side views of a brachial valve distorted by crowding and having an old adult cardinal process, X 1, hypotype USNM 154179a; 9, 10, ventral and side views of a pedicle valve with a great brush of rhizoid spines on the ears, x 1, hypotype USNM 149024b; 12-14, interior, side, and posterior views of a small brachial valve with strongly adult cardinal process, x 1, hypotype USNM 154179J; 15-17, posterior, side, and interior views of another brachial valve approximately the same size as the preceding one but having a juvenile cardinal process, x 1, hypotype USNM 154179g. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1369 PLATE 226.-Echinosteges 1370 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 227 Echinosteges Echinosteges tuberculatus (R. E. King): 1-5, Interior tilted slightly posteriorly, interior, exterior, posterior, and side views of a large, obese brachial valve, X 1, showing greatly expanded cardinal process and thick adductor callosities, hypotype USNM 154179k; 6-9, interior slightly tilted posteriorly, posterior, side, and exterior views of another brachial valve, approximately the same size as the preceding but with poorly developed adductor callosities and a cardinal process still in a juvenile stage, x 1, hypotype USNM 154179-1; 10-12, posterior, side, and interior views of a young brachial valve with juvenile cardinal process, X 1, hypotype USNM 154179b; 13-15, side, posterior, and interior views of another obese brachial valve, x 1, hypotype USNM 154179c; 20-22, side, posterior, and interior views of a precocious, young brachial valve with expanded cardinal process and thickened adductor platforms, x 1, hypotype USNM 154179f; 23-25, posterior, side, and interior views of a brachial valve about equal in size to the preceding but retarded and having a juvenile cardinal process, X 1, hypotype USNM 154179d. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] 16, Small pedicle valve attached to Rhamnaria, X 1, hypotype USNM 149019d; 17-19, side, posterior, and interior views of a medium-sized brachial valve with strongly lobate cardinal process, X 1, hypotype USNM 123905f. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1371 PLATE 227.-Echinosteges 1372 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 228 Echinosteges Echinosteges tuberculatus (R. E. King): 1, 2, Interior of an immature brachial valve, x 1, X 3, showing V-shaped cardinal process, hypotype USNM 123905e; 3, 4, interior, X 1, X 2, of another immature brachial valve, hypotype USNM 154180p; 5-7, posterior, side, and interior, X 1, of another brachial valve, hypotype USNM 154180q; 8-10, posterior, side, and interior views of a young brachial valve, X 1, showing a well developed cardinal process, hypotype USNM 154180f; 11, interior of a young brachial valve, X 1, hypotype USNM 123453-1; 12, 13, side and in- terior views of the same brachial valve, X 2, showing the immature cardinal process; 14-16, posterior, side, and interior views of a young brachial valve, x 1, with juvenile cardinal process, hypotype USNM 154180n; 17-19, side, posterior, and interior views of a brachial valve equal in size to the preceding but having an advanced, lobate cardinal process, X 1, hypotype USNM 154180-1; 20-22, posterior, side, and interior views of a small brachial valve with advanced internal characters, x 1, hypotype USNM 154180k; 23-25, side, posterior and interior views of a fairly large specimen with retarded cardinal process, x 1, hypotype USNM 154180b; 26-28, posterior, side, and interior views of a large brachial valve with retarded cardinal process, X 1, hypotype USNM 154180a; 29-31, posterior, side and interior views of a medium-sized brachial valve having juvenile interior characters, X 1, hypotype USNM 154180o; 32-34, posterior, side, and interior views of an obese brachial valve having a strongly lobed cardinal process and prominent marginal flange, X 1, hypotype USNM 154180c; 35-37, posterior, side, and interior views of a specimen equal in size to that illustrated in figures 29-31 but having greatly advanced interior characters, x 1, hypotype USNM 154180g; 38-40, posterior, side, and interior views of a brachial valve with marginal flange, a sure sign of old age, but with a juvenile-type cardinal process, x 1, hypotype USNM 154178m; 41-43, posterior, side, and interior views of an old brachial valve, comparable in age to the preceding specimen but having a strongly lobed cardinal process, x 1, hypotype USNM 154178-1. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1373 PLATE 228.-Echinosteges ~*..r-- - 1374 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 229 Echinosteges Echinosteges guadalupensis (Shumard): 1-3, Exterior, side, and interior views of a brachial valve, X 1, showing the V-shaped cardinal process, hypotype USNM 152652-1; 4-6, interior, side, and exterior views of another brachial valve, x 1, hypotype USNM 152652m; 7-9, side, interior, and ventral views of a small pedicle valve, X 1, hypotype USNM 152652c; 10-12, side, interior, and exterior views of a pedicle valve with some of its rhizoid spines preserved, X 1, hypotype USNM 152652a (for enlargement, see plate 258: figure 30); 15, posterior view of a brachial valve, X 1, hypotype USNM 152652J. [Bell Canyon Formation (Rader Member), USNM 725f.] 13, 14, Interior and posterior of a fragmentary brachial valve, x 1, hypotype USNM 154181. [Bell Canyon Formation (Hegler Member), USNM 731.] 16-18, Interior, side, and exterior views of a large brachial valve, X 1, showing anteriorly open cardinal process, hypotype USNM 149407. [Bell Canyon Formation (Pinery Member), USNM 736.] 19, Interior of a fragmentary brachial valve, X 1, hypotype USNM 154182a. [Bell Canyon Formation (Radcr Member), AMNH 403.] Echinosteges tuberculatus (R. E. King): 20, Dorsal view of a small specimen with both valves in contact, X 1, hypotype USNM 149020u; 21, ventral view of a young specimen, x 1, showing its body spines, hypotype USNM 149019e; 22, 23, ventral and interior views of a small pedicle valve, X 1, hypotype USNM 154178h; 24, dorsal view of a complete specimen distorted by crowding, x 1, hypotype USNM 149019f; 25, ventral view of two immature specimens pre- serving their rhizoid spines, X 1, hypotypes USNM 149019g, h; 26, ventral view of pedicle valve pre- serving its long rhizoid spines, X 2, hypotype USNM 123905h; 27, 28, side and ventral views of a young pedicle valve, X 1, hypotype USNM 154178J; 29, young specimen attached to a fenestel- lid frond, X 1, hypotype USNM 154178e; 30, 31, interior and exterior of an immature pedicle valve, X 1, hypotype USNM 154178k; 32-34, side and ventral views, x 1, and side, X 2, of a young specimen attached to a pedicle valve of Echinauris, hypotype USNM 149019i; 35, side view of another young, attached specimen, X 1, hypotype USNM 149019J; 36, ventral view of a young attached specimen, X 1, USNM 149019-1; 37, 38, interior and exterior of an immature pedicle valve, X 1, hypotype USNM 149019m. [Word Formation (Willis Ranch Member), USNM 706e.] NUMBER 19 1375 PLATE 229.-Echinosteges 2376 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 230 Cactosteges Cactosteges anomalus, new species: 1-7, Ventral, dorsal, posterior, anterior, and side views, X 1, and dorsal and ventral views, x 2, of the holotype, USNM 151297a; 8-13, anterior, interior, pos- terior, side, and ventral views, X 1, and interior view, x 2, of a pedicle valve, showing muscle area, paratype USNM 151297f; 14-18, dorsal, posterior, side, ventral, and anterior views of a small adult, x 1, paratype USNM 151297d; 31-36, posterior, interior, interior tilted, side, ventral, and anterior views of a pedicle valve, x 1, paratype USNM 151297e; 37-39, posterodorsal, posterior, and interior views of a brachial valve, X 2, showing lobed cardinal process and excessive development of endospines, paratype USNM 154152b; 40, 41, interior and posterior views of another brachial valve with thickened cardinal process, X 2, paratype USNM 154152c; 42, interior of a brachial valve, X 3, showing an immature cardinal process, paratype USNM 154152d; 43, interior of another brachial valve damaged by overcrowding, x 3, paratype USNM 154152e; 45, brachial valve interior, x 3, showing adductor scars and a few endospines, paratype USNM 154152f; 46, interior of an obese brachial valve with greatly thickened cardinal process, X 3, paratype USNM 154152g; 47, interior of a brachial valve, x 2, showing rows of beads inside hinge, paratype USNM 154152h; 48, interior of a brachial valve, x 3, showing immature cardinal process, paratype USNM 154152i; 49, another brachial valve interior, x 3, showing brachial ridges, endospines and normal cardinal process, paratype USNM 154152J. [Word Formation (Willis Ranch Member), USNM 706.] 44, Interior of a brachial valve with stout cardinal process, X 3, paratype USNM 154150c [Word Formation (Willis Ranch Member), USNM 724u.] 19-24, Dorsal view, X 2, and dorsal, anterior, posterior, side, and ventral views, X 1, of a complete specimen, paratype USNM 154151c; 25-30, posterior, ventral, side, anterior, and posterior views, x I, and dorsal view, X 2, of a complete paratype, USNM 154151d. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1377 PLATE 230.-Cactosteges * 13 1378 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 231 Agelesia, Spyridiophora, and Cactosteges Agelesia triagonalis (R. E. King): 1-5, Dorsal, side, ventral, anterior, and posterior views of a complete specimen preserving some of its rhizoid spines, x 1, hypotype USNM 151516b; 11-15, posterior, side, anterior, ventral, and dorsal views of a complete specimen devoid of spines, X 1, hypotype USNM 151516e; 16-19, posterior and interior, X 2, and exterior and interior, X 1, of a brachial valve, hypotype USNM 151514a; 20-23, exterior and interior, X 1, and posterior and interior, X 2, showing adductor platforms and bilobed cardinal process, hypotype USNM 151514b; 25-28, anterior, posterior, side, and dorsal views of a complete specimen, X 1, preserving some of its rhizoid spines, hypotype USNM 153834e; 29, 30, dorsal and ventral views X 1, of a squarish specimen, hypotype USNM 153834f; 31, interior of a pedicle valve, X 1, preserving some of the rhizoid spines and showing the apical muscle callosity, hypotype USNM 151515a. [Cathedral Mountain Formation, USNM 703bs.] 6-10, Anterior, dorsal, side, ventral, and posterior views of a complete specimen but lacking its spines, X 1, hypotype USNM 151520d; 24, dorsal view of another specimen lacking its spines, X 1, hypotype USNM 151520b. [Cathedral Mountain Formation (Wedin Member), USNM 714w.] 35-38, Side, ventral, posterior and anterior views, x 1, of the holotype YPM 11883; 39-41, anterior, dorsal, and ventral views, X 2, of the holotype. [Cathedral Mountain Formation, R. E. King locality 247.] 42, 43, Ventral and dorsal views of a paratype, T11014. [Cathedral Mountain Formation, R. E. King locality Tx.] Spyridiophora reticulata (R. E. King): 32, Exterior of an imperfect pedicle valve, x 1, hypotype USNM 154149a; 33, 34, interior of the brachial valve, X 1, X 2, showing raised adductor plat- forms, hypotype USNM 154149b. [Cathedral Mountain Formation, USNM 721u.] Cactosteges anomalus, new species: 44-46, Posterodorsal, posterior, and interior views of the brachial valve, X 2, paratype USNM 154150a; 52, interior of a pedicle valve, X 2, showing interarea, paratype USNM 154150b. [Word Formation (Willis Ranch Member), USNM 724u.] 47, 48, Interior and exterior of a brachial valve, x 2, showing the trilobed cardinal process, paratype USNM 154151a; 49, 50, exterior and interior views of another brachial valve, X 2, showing adductor platforms, paratype USNM 154151b. [Word Formation (China Tank Member), USNM 706c] 51, Ventral view of a pedicle valve, x 2, showing the short body spines and long rhizoid spines, paratype USNM 151296a; 55, another pedicle valve, X 2, showing the same features as the preceding specimen, paratype USNM 151296b; 56, interior of a pedicle valve tilted pos- teriorly to show elevated muscle scars, X 2, paratype USNM 154152a. [Word Formation (Willis Ranch Member), USNM 706.] 53, 54, Side and ventral views of a specimen attached to a tetracoral, X 2, showing numerous rhizoid spines, paratype USNM 151298. [Word Formation (Willis Ranch Member), USNM 706e.] NUMBER 19 1379 PLATE 231.- Agelesia, Spyridiophora, and Cactosteges 1380 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 232 Xenosteges Xenosteges adherens Muir-Wood and Cooper: 1, Ventral view of an immature pedicle valve, X 1, showing rhizoid spines, hypotype USNM 154236 (for enlarged view, see plate 233: figure 40); 4-6, ventral, side, and dorsal views, X 1, of a wide specimen, hypotype USNM 149230c; 7-9, exterior, side, and interior views, X 1, of a brachial valve, hypotype USNM 149230d. [Cathedral Mountain Formation, USNM 703b.] 2. Ventral view of two immature pedicle valves, X 1, hypotypes USNM 154248a, b; 3, ventral view of the lower of the preceding two specimens enlarged, X 3, to show the rhizoid spines. [Cathedral Mountain Formation, USNM 702b.] 10-12, Posterior, interior, and exterior views of a brachial valve, X 2, hypotype USNM 154249b; 13-18, dorsal, ventral, side, anterior, and posterior views, x 2, and dorsal view, x 1, of a complete specimen, hypotype USNM 154249d; 19-23, ventral, posterior, side, dorsal, and anterior views, X 2, of a complete specimen, hypotype USNM 154249c; 24-28, ventral, interior, side, and anterior views, X 2, and ventral view, x 1, of a large pedicle valve, hypotype USNM 154249a. [Cathedral Mountain Formation, USNM 721u.] 29, Interior view of a small attached pedicle valve, X 1, showing long rhizoid spines, hypotype USNM 154250. [Cathedral Mountain Formation, USNM 702un.] 30-35, Ventral view, X 1, and anterior, side, interior, exterior, and posterior views, X 2, of a large pedicle valve, hypotype USNM 154251a; 36-38, ventral and interior views, X 2, and ventral view of an attached pedicle valve, X 1, showing rhizoid spines, hypotype USNM 154251d; 39-43, ventral, posterior, side, interior, and anterior views, X 2, of a large brachial valve, hypotype USNM 154251b; 44, 45, exterior and interior, x 2, of a brachial valve, hypotype USNM 154251c [Cathedral Mountain Formation, USNM 726u.] 46, 47, Interior of a Lepidospirifer pedicle valve, X 1, X 2, with attached Xenosteges, paratype USNM 124128a, and showing long rhizoid spines; 48, Xenosteges attached inside the pedicle valve of Hercosia, x 2, hypotype USNM 149170. [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1381 PLATE 232.-Xenosteges 1382 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 233 Hystriculina and Xenosteges Hystriculina sulcata, new species: 1, Ventral view of three immature pedicle valves, X 1, para- types USNM 154235b,c,a; 2, topmost specimen of preceding three, X 3; 3, middle specimen, X 3; 4, bottom specimen x 3; 20-26, anterior, posterior, ventral dorsal, and side views, X 1, and dorsal and ventral views, X 2, of a complete specimen, paratype USNM 154235e; 27-31, dorsal, anterior, side, posterior, and ventral views, X 1, of a complete specimen, paratype USNM 154235f. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] 5-9, Ventral, anterior, dorsal, posterior, and side views, X 1, of a complete specimen, paratype USNM 149718-1; 10-14, 32, 33. Ventral, posterior, side, dorsal, and anterior views, X 1, and dorsal and ventral views, X 2, of the holotype USNM 149718b; 15-19, posterior, ventral, anterior, side, and dorsal views, X 1, of another complete specimen, paratype USNM 149718n; 34-36, interior, and exterior, x 2, and posterior, x 3, showing the cardinal process, endospines, and ear baffles, paratype USNM 149718o; 37-39, interior, exterior, x 2, and posterior, X 3, of another brachial valve, paratype USNM 149718p. [Neal Ranch Formation, USNM 701.] Xenosteges adherens Muir-Wood and Cooper: 40, Ventral view of an immature pedicle valve, X 6, showing early rhizoid spines, hypotype USNM 154236 (for X 1 view see plate 232: figure 1). [Cathedral Mountain Formation, USNM 703b.] Xenosteges umbonatus, new species: 41-46, Anterior, posterior, side, ventral, and dorsal views, X 2, and dorsal view, x I, paratype USNM 149217h; 47-50, side, ventral, anterior, and interior views, X 2, of a pedicle valve, paratype USNM 149217b; 51-53, interior, ventral, and side views of a pedicle valve, x 2, showing muscle platform, paratype USNM 149217a; 54-58, dorsal, ventral, posterior, anterior, and side views, X 2, of the holotype USNM 149217d, showing bases of the rhizoid spines; 59-62, ventral, interior, and side views of a laterally expanded pedicle valve, x 2, paratype USNM 149217f. [Bell Canyon Formation (Hegler Member), USNM 731.] NUMBER 19 1383 PLATE 233.-Hystriculina and Xenosteges 1384 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 234 Xenosteges Xenosteges magnus, new species: 1, Specimen attached inside the pedicle valve of a lyttoniid, X 1, paratype USNM 154237. [Road Canyon Formation, USNM 721o.] 2, 3, Interior, x 2, and exterior, x 1, of a large pedicle valve, showing its rhizoid spines and muscle region, paratype USNM 154238. [Road Canyon Formation, USNM 719x.] 4-10, Anterior, posterior, dorsal, side, and ventral views, X 1, and ventral and dorsal views, X 2, of a large pedicle valve preserving part of its rhizoid spines, holotype USNM 152653a. [Road Canyon Formation, USNM 726d.] 11, 12, Ventral view, x 1, X 2, of an attached specimen, paratype USNM 152654. [Road Canyon Formation, USNM 721x.] 13-16, Side, interior, and exterior views, X 1, and interior, x 2, of a brachial valve, paratype USNM 154239a; 17-20, 27, posterior, side, ventral, and anterior views, X 1, and interior, X 2, of a pedicle valve, showing rims of spines in the interior, paratype USNM 154239b; 21-26, side, dorsal, anterior, posterior, and ventral views of a complete specimen, x 1, and dorsal view, X 2, paratype USNM 154239c [Road Canyon Formation, USNM 721j.] Xenosteges adherens Muir-Wood and Cooper: 28, Ventral view of a young pedicle valve showing one long rhizoid spine, X 1, hypotype USNM 149170; 29, dorsal view of a complete specimen with laterally directed rhizoid spines, X 2, paratype USNM 124128b. [Cathedral Mountain Formation, USNM 702.] Ventral view, x 2, of a young specimen, paratype USNM 124129a. [Cathedral Mountain Formation, USNM 702un.] Dorsal view of a complete specimen, x 2, paratype USNM 124130a; 32, ventral view of a pedicle valve, x 1, showing laterally extended rhizoid spines, paratype USNM 124130b. [Cathedral Mountain Formation, USNM 702a.] Xenosteges anomalus, new species: 33-35, Interior, exterior, X 2, and interior, X 1, showing a stout rhizoid spine, paratype USNM 154240a; 36-38, exterior, and interior, X 2, and interior, X 1, of another pedicle valve, paratype USNM 154240b; 39-41, dorsal, ventral, and side views of a complete specimen, x 1, holotype USNM 154241a (for X 2 views, see Plate 244: figures 38-42); 42-44, ventral, posterior, and anterior views, x 1, of another paratype USNM 154241d; 45-47, dorsal view, x 1, and dorsal and ventral views, x 2, showing both valves, paratype USNM 154241b; 48, 49, exterior and interior, x 2, of a brachial valve, paratype USNM 154240c; 50, interior of another brachial valve, X 2, showing submarginal rim, paratype USNM 154240d; 51, interior of an obese brachial valve, X 4, showing submarginal rim, brachial ridges, adductor callosities and cardinal process, paratype USNM 154240c [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1385 PLATE 2M.-Xenosteges 1386 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 235 Xenosteges Xenosteges quadratus, new species: 1-5, Interior, ventral, anterior, and side views, X 2, and ventral view, x 1, of a large pedicle valve, showing muscle platform, paratype USNM 149200a; 11-14, dorsal, side, ventral, and anterior views of a complete specimen, x 2, paratype USNM 149200c; 55-59, dorsal view, x 1, and anterior, side, ventral, and dorsal views, X 2, holotype USNM 154246a. [Word Formation (Willis Ranch Member), USNM 706c] 6-10, Exterior, anterior, interior, and side views, X 2, and posterior view, x 3, of a brachial valve, showing elevated brachial ridges, paratype USNM 154242a; 20-25, ventral view, X 1, and side, interior, ventral, oblique, and anterior views, X 2, of a pedicle valve, paratype USNM 154242b. [Cherry Canyon Formation (Getaway Member), USNM 728.] 15-18, Ventral view, x 1, and ventral, side, and dorsal views, x 2, of an attached specimen, paratype USNM 154244a. [Word Formation (Willis Ranch Member), USNM 724u.] 19, Ventral view of a specimen attached to a bryozoan, x 2, paratype USNM 154243c; 26-30, ventral, anterior, side, and interior views, x 2, and ventral view, x 1, of a large pedicle valve, paratype USNM 154243d; 31, anterior view of a specimen attached to a small Derbyia, x 2, paratype USNM 154243a; 52, specimen attached inside the pedicle valve of Echinauris, x 2, paratype USNM 149193; 60, ventral view of a specimen attached to a bryozoan, X 2, paratype USNM 154243b. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] 32-36, Ventral view, x 1, ventral, interior, and anterior views, X 2, of a pedicle valve, para- type USNM 154245a; 37-41, anterior and interior views, X 2, posterior view, x 3, and interior view, x 4, of a brachial valve, showing exaggerated brachial ridges, paratype USNM 154245b; 42-45, exterior and interior views, X 2, posterior view, X 3, and interior view, X 4, of a brachial valve distorted by crowding and showing great development of the brachial ridges, paratype USNM 154245c [Word Formation (Willis Ranch Member), USNM 706.] 46-51, Dorsal view, X 1, and posterior, anterior, ventral, and dorsal views, x 2, of a complete specimen, paratype USNM 149197; 53, 54, ventral and interior views of a pedicle valve, X 1, attached to Enteletes, paratype USNM 149196. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1387 PLATE 2S5.-Xenosteges ***'?"<'?.,??* :,r 60 1388 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 236 Xenosteges Xenosteges quadratus, new species: 1-5, Ventral, interior, anterior, and side views, X 2, and ventral view, x 1, of a pedicle valve, paratype USNM 154246b; 6-11, exterior view, X 1, anterior, exterior, interior, and posterior views, X 2, and posterodorsal view, x 3, showing elevated brachial ridges, and cardinal process, paratype USNM 154246c; 12-18, exterior view, X 1, anterior, interior, exterior, and side views, X 2, posterior view, x 3, and interior view, x 4, showing brachial ridges, paratype USNM 154246d. [Word Formation (Willis Ranch Member), USNM 706c] Xenosteges trivialis, new species: 19-23, Side, dorsal, ventral, anterior, and posterior views, X 2, holotype USNM 152655c; 24-26, exterior, interior, X 2, posterior view, x 3, showing cardinal process, paratype USNM 152655d; 27-31, ventral, posterior, anterior, side, and interior views, X 2, of a pedicle valve, paratype USNM 152655a. [Road Canyon Formation, USNM 721z.] 32-34, Ventral oblique view, x 1, and oblique and interior views, x 2, showing attached specimen with hold strengthened by a stout rhizoid spine, paratype USNM 152656c; 35, ventral view of another attached specimen, x 2, paratype USNM 152656f; 36-41, interior, X 1, and ventral, posterior, interior, anterior, and side views, X 2, of a pedicle valve, paratype USNM 152656h; 42-46, side, exterior, anterior, and interior views, X 2, and posterior view, x 3, of a brachial valve showing cardinal process, paratype USNM 152656g; 47-51, posterior, side, ventral, anterior, and dorsal views of a complete specimen, x 2, paratype USNM 152656e; 52-56, dorsal view, X 1, and anterior, side, dorsal, and ventral views, X 2, of another complete specimen, paratype USNM 152656d. [Road Canyon Formation, USNM 724c] Xenosteges umbonatus, new species: 57-59, Exterior and interior views, X 2, and exterior view, X 1, of a brachial valve, paratype USNM 154247a; 60, 61, ventral views of a pedicle valve, X 1, X 2, paratype USNM 154247b; 62-64, exterior, x 1, and interior and exterior, x 2, of another brachial valve, paratype USNM 154247d; 65-67, exterior and interior, x 2, and exterior, X 1, of a brachial valve showing elevated brachial ridges, paratype USNM 154247e; 68-70, in- terior and exterior, X 2, and exterior, X 1, of another brachial valve with thickened adductor callosities, paratype USNM 154247c [Bell Canyon Formation (Hegler Member), AMNH 635.] NUMBER 19 1389 PLATE 236.-Xenosteges 1390 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 237 Scapharina and Kutorginella Scapharina levis, new species: 1-4, Interior, exterior, and posterior, X 3, and exterior, X 1, of a brachial valve showing ear baffles, cardinal process, and brachial ridges, paratype USNM 154224a; 5-8, dorsal, ventral, and posterior views, x 3, and dorsal view, x 1, of a complete specimen, paratype USNM 154224b. [Bell Canyon Formation (Pinery Member), AMNH locality 375.] 21-23, Ventral, X 1, and interior and ventral, x 3, views of a pedicle valve, showing fluted ear baffles, paratype USNM 149223d; 24, 25, interior and exterior views of a battered brachial valve, showing ear baffles, X 3, paratype USNM 149223g; 26, 27, exterior and interior of another brachial valve, x 3, showing ear baffles and marginal rim, paratype USNM 149223e; 28-31, ex- terior, posterior, interior, and side views of a brachial valve, X 3, paratype USNM 152658f; 32-37, side, ventral, anterior, dorsal views, X 3, and dorsal view, x 1, of a complete specimen, paratype USNM 152658a; 38-43, ventral and dorsal views, x 1, and side, ventral, anterior, and dorsal views, X 3, paratype USNM 152658c; 44-49, ventral and dorsal views, X 1, and anterior, ventral side, and dorsal views, x 3, of a complete specimen preserving part of its large, scattered rhizoid spines, holotype USNM 152659; 50-55, ventral and dorsal views, X 1, and ventral side and dorsal views, X 3, of another complete specimen, paratype USNM 152658b. [Bell Canyon Formation (Lamar Member), USNM 738b.] Kutorginella sullivanensis (R. E. King): 9-12, Side, dorsal, posterior, and ventral views of the holotype, X 1, YPM 10767. [Road Canyon Formation, R. E. King locality 46.] Scapharina quadrata, new species: 13-16, Interior, ventral, and posterior views, X 3, and ventral view, x 1, of a pedicle valve, paratype USNM 154225a; 17-20, posterior, interior, and exterior views, X 3, and exterior, X I, of a brachial valve showing breviseptum cardinal process, and brachial ridges, paratype USNM 154225b. [Bell Canyon Formation (Hegler Member), USNM 731.] NUMBER 19 1391 PLATE 237.-Scapharina and Kutorginella 1392 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 238 Scapharina Scapharina quadrata, new species: 1, 2, Ventral views of a pedicle valve, X 1, X 2, holotype USNM 152660a; 3-5, ventral and interior views, X 3, and exterior, X 1, of a pedicle valve, para- type USNM 152660b; 6, 7, interior and posterior of a damaged brachial valve interior, X 3, showing brachial ridges and submarginal ridge, paratype USNM 152660d; 8-11, dorsal view, X 1, and exterior, posterior, and interior views of another brachial valve, X 3, paratype USNM 152660c; 12-14, interior, posterior, and exterior views of a brachial valve with well developed cardinal process, x 3, paratype USNM 152660e; 15-17, interior, exterior, and posterior views of the preceding specimen, x 6, showing brachial ridges, breviseptum adductor scars; 18, exterior of the preceding specimen, X 1. [Bell Canyon Formation (Hegler Member), USNM 731.] Scapharina levis, new species: 19, Interior of the brachial valve, X 6, showing cardinal process, paratype USNM 152658L [Bell Canyon Formation (Lamar Member), USNM 738b.] Scapharina rugosa, new species: 20-23, Ventral, side, anterior, and interior views of a pedicle valve, X 3, paratype USNM 154227a; 24-28, dorsal view, x 1, and dorsal, ventral, anterior and side views, X 3, of a complete specimen, paratype USNM 154227d; 29, dorsal view of a complete specimen, x 3, paratype USNM 154227c; 30-34, side, interior, and exterior, X 3, and interior and exterior, x 6, of a brachial valve showing submarginal rim, brachial ridges and cardinal process, paratype USNM 154227e; 35, 36, exterior and interior of another brachial valve, X 3, paratype USNM 154227f; 37, dorsal view of a complete specimen, x 1, paratype USNM 154227g; 38-42, anterior, interior, side, and exterior views, x 3, and interior, x 6, of a brachial valve showing a thickened cardinal process and strong submarginal rim, paratype USNM 154227h. [Bell Canyon Formation (Hegler Member), USNM 731.] NUMBER 19 1393 PLATE 23S.-Scapharina 1394 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 239 Scapharina Scapharina rugosa, new species: 1, 2, Exterior and interior of a pedicle valve, X 3, showing rugose surface, paratype USNM 154228a; 3-6, exterior, x 1, X 3, and interior, x 3, X 6, show- ing cardinal process and adductor scars, of a rugose brachial valve, paratype USNM 154228b. [Bell Canyon Formation (Hegler Member), AMNH 635.] 7-10, Side, anterior, ventral, and dorsal views of a complete specimen, X 3, paratype USNM 152657a; 11-14, ventral, side, dorsal, and anterior views of another complete specimen, x 3, paratype USNM 152657c; 15, 16, interior and exterior views of a pedicle valve, X 3, showing well developed ears, paratype USNM 152657b; 17-20, dorsal, ventral, side, and anterior views of a strongly rugose individual, x 3, holotype USNM 152657d; 21-23, dorsal, anterior, and ventral views of a rugose specimen, x 3, paratype USNM 152657e; 24-28, interior, posterior, and side views, x 3, and interior and side views, x 6, of a brachial valve, showing ear baffles merging into submarginal rim, brachial ridges and small cardinal process, paratype USNM 152657f; 54-56, anterior, side, and dorsal views of a rugose individual, X 3, paratype USNM 154227b. [Bell Canyon Formation (Hegler Member), USNM 731.] 29-32, Dorsal, side, anterior, and ventral views of a specimen distorted by crowding, x 3, paratype USNM 154226c; 33-37, dorsal, X 1, and dorsal, side, anterior, and ventral views, X 3, of a greatly thickened and rugose individual, x 3, paratype USNM 154226d; 38-42, interior view, X 1, and interior, anterior, ventral, and side views, X 3, paratype USNM 154226e; 43-46, side, in- terior, exterior, and anterior views of a brachial valve, X 3, showing the strong submarginal rim, paratype USNM 154226b; 47-50, side, interior, exterior and posterior views of another brachial valve, x 3, paratype USNM 154226a; 51, 52, interior and side views of the preceding specimen, X 6, showing brachial ridges, submarginal rim and cardinal process; 53, dorsal view of a brachial valve, X 3, paratype 154226L [Bell Canyon Formation (Rader Member), USNM 725f.] NUMBER 19 1395 PLATE 2S9.-Scapharina n3i 7 1396 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 240 Chonosteges Chonosteges limbatus, new species: 1-6, Dorsal, ventral, side, and anterior views, X 2, and dorsal and ventral views, X 1, of a complete specimen, paratype USNM 154156a; 7, 8, anterior views, X 1, X 2, of an attached specimen, paratype USNM 154156b. [Hess Formation (Taylor Ranch Member), USNM 702c] 9-14, Dorsal, side, anterior, and ventral views, x 2, and ventral and dorsal views, X 1, of a complete specimen with long, sleevelike marginal flange on the brachial valve, holotype USNM 149285a. [Hess Formation (Taylor Ranch Member), USNM 702d.] Chonosteges matutinus, new species: 15-20, Dorsal, ventral, and anterior views, X 1, and dorsal, anterior, and ventral views, X 2, of the holotype USNM 149288b; 21-24, ventral view, X 1, and side, anterior, and ventral views, X 2, of a pedicle valve, paratype USNM 149288a; 25-28, an- terior, side and ventral views, X 2, and side, x 1, of another pedicle valve, paratype USNM 149307b; 29-33, anterior and ventral views, x 1, and ventral, anterior, and side views, X 2, of another paratype, USNM 149307a. [Skinner Ranch Formation (Decie Ranch Member, USNM 707a.] Chonosteges multicostatus, new species: 34, Ventral view, x 2, showing specimen before genicu- lation, paratype USNM 149301a; 35, exterior of the brachial valve, X 2, paratype USNM 149301b; 36-41, side, dorsal, anterior, and ventral views, X 2, and ventral and dorsal views, X 1, of the holotype, USNM 149301c; 42-45, anterior, side, dorsal, and ventral views of another complete specimen, x 2, paratype USNM 149301d; 46-49, anterodorsal, dorsal, and anterior views, X 2, and dorsal view, X 1, of a specimen with intake funnels crowded along the anterior margin of the brachial valve, paratype USNM 149301e; 50, 51, dorsal view of another specimen with crowded intake funnels, X 1, X 2, paratype USNM 149301 f. [Cathedral Mountain Formation, USNM 703bs.l NUMBER 19 1397 PLATE 240.-Chonosteges m ? y%Wrrjr^ M-*" ,\J& m 37 39 1398 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 241 Chonosteges Chonosteges pulcher, new species: 1-6, Dorsal, ventral, anterior, and side views, X 2, and dorsal and ventral views, x 1, of the paratype USNM 149280b; 32-34, dorsal, ventral, and side views of another complete specimen, x 2, paratype USNM 149280c [Cathedral Mountain Formation (Wedin Member), USNM 717c] Anterior view of a specimen attached to a fenestellid frond, x 1, paratype USNM 154163a; 12, anterior view of a specimen with valves agape, X 3, showing the intake funnels, and strainer points, paratype USNM 154163b; 13, dorsal view of the preceding specimen, x 2, showing the intake funnels; 23-25, exterior, anterior, and interior views of a brachial valve, x 2, showing intake tubes, paratype USNM 154163c; 48, anterior of a gaping specimen, X 2, showing the strainer needles on the brachial valve, paratype USNM 154163d. [Cathedral Mountain Forma- tion (Wedin Member), USNM 714w.] Specimen attached to the brachial valve of Institella, x 1, paratype USNM 154164a; 26, 27, anterior view of two attached specimens, X 1, and anterior view of the lower specimen, x 2, showing rhizoid spines and intake funnels, paratype USNM 154164c; 28-31, dorsal view, X 1, and side, dorsal, and anterior views, X 2, of a complete specimen showing strong marginal sleeve of the brachial valve, paratype USNM 154164b. [Cathedral Mountain Formation (Wedin Mem- ber), USNM 727p.] Exterior of an immature pedicle valve, X 1, showing hairlike ornament spines, paratype USNM 154165a; 14-16, exterior, partial anterior, and anterior views of a brachial valve, X 2, showing intake tubes, paratype USNM 154165c; 21, 22, dorsal and anterior views of a complete specimen with intake tubes, x 2, paratype USNM 154165d; 40-43, ventral, dorsal, side and anterior views of a complete specimen, x 2, paratype USNM 154165b. [Cathedral Mountain Formation (Wedin Member), USNM 723u.] 10, 11, Interior and exterior of an immature specimen, X 2, showing the open, V-shaped cardinal process, paratype USNM 154157b (for enlargement see plate 244: figure 8); 35, 36, ex- terior and interior of a distorted brachial valve, X 2, paratype USNM 154157i; 44-47, ventral, dorsal, anterior, and side views of a complete individual, x 2, paratype USNM 154157-1. [Cathedral Mountain Formation, USNM 721u.] 17, 18, Dorsal, and ventral views of a complete specimen, x 1, paratype USNM 149294; 37-39, ventral, side, and dorsal views X 2, of the preceding specimen. [Cathedral Mountain Formation, AMNH 504.] 19, 20, Ventral and interior views of a pedicle valve preserving some of its rhizoid spines, X 1, paratype USNM 154166. [Cathedral Mountain Formation, USNM 702.] 49-52, Dorsal view, x 1, and dorsal, side, and anterior views, X 2, of a complete attached specimen, showing the flanges or sleeves of both valves, that of the brachial valve slipping over that of the pedicle valve, paratype USNM 154167a. [Cathedral Mountain Formation (Wedin Member), USNM 723v.] NUMBER 19 1399 PLATE 241.- Chonosteges 1400 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 242 Chonosteges Chonosteges costellatus, new species: 1-5, Dorsal, ventral, anterior, and side views, X 2, and dorsal view, x 1, of a complete specimen, paratype USNM 149275e; 6-9, ventral, anterior, dorsal, and side views of another complete individual, X 2, paratype USNM 149275f; 26, ventral view of a pedicle valve with rhizoid and ornament spines, X 2, paratype USNM 154169a; 28, an- terior of a gaping specimen showing the needle-like strainer spines, X 2, paratype USNM 154169c; 29, 30, two specimens in attached position, x 1, showing the mode of growth, paratypes USNM 154169g, h; 31, ventral view of an immature specimen, not yet geniculated, X 2, paratype USNM 154169b; 37-40, posterodorsal, interior, and exterior views, X 2, and posterior view, X 3, showing cardinal process, paratype USNM 154169e; 41-44, posterodorsal, interior, and exterior views, X 2, and posterior view, x 3, showing moderately developed cardinal process, paratype USNM 154169d; 45-47, posterior, x 3, interior, and exterior views, X 2, of a young brachial valve, paratype USNM 154169f. [Cathedral Mountain Formation, USNM 703a1.] 10-14, Ventral and dorsal views, X 1, and anterior, side, arid ventral views, X 2, of a com- plete specimen, paratype USNM 154168a; 15-17, ventral and interior views, X 2, and interior view, x 1, of a pedicle valve showing the adductor callosity, paratype USNM 154168b; 18-20, interior view, x 1, and interior and exterior views, X 2, showing interarea, paratype USNM 154168d; 21, 22, exterior, and interior of a brachial valve, X 2, showing the brachial ridges, para- type USNM 154168c; 23-25, exterior and interior, x 2, and exterior, x 1, of another brachial valve, paratype USNM 154168c [Cathedral Mountain Formation, USNM 726u.] 27, Exterior of a young pedicle valve, x 2, paratype USNM 154170a; 32-36, dorsal view, X 1, and dorsal, ventral, side, and anterior views, X 2, of the holotype USNM 152661a; 48, 49, dorsal views of another complete specimen, x 1, X 2, paratype USNM 154170b. [Cathedral Mountain Formation, USNM 726o.] NUMBER 19 1401 PLATE 242.-Chonosteges 6 6 ;' jv M&tifii ?<& 1402 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 243 Chonosteges Chonosteges variabilis, new species: 1, Interior of brachial valve of Neospirifer occupied by two specimens of Chonosteges variabilis, X 2, paratype USNM 123901; 2, dorsal view of the right hand individual of the preceding specimens, X 3, showing anchor spines and intake tubes; 3, an- terior view of the preceding specimen, x 3, showing the intake funnels; 4, dorsal view of a complete specimen devoid of spines, X 1, paratype USNM 124131a; 8, oblique view of the anterior of a specimen showing its numerous anchor spines, X 3, paratype USNM 124132b; 12, ventral view of a specimen attached to Rugatia, X 1, paratype 154153b; 15, ventral view of an immature specimen, x 1, showing hairlike ornament spines and lack of marginal develop- ment, paratype USNM 154153c; 16, ventral view of a complete specimen, X 2, showing genicu- lating margins, paratype USNM 149251; 19, anterior of another specimen, X 3, showing rhizoid spines and the ventrally geniculated border of the brachial valve, paratype USNM 124132a. [Cathedral Mountain Formation, USNM 702.] 5, Ventral view of an immature specimen, X 1, showing hairlike ornament spines and the beginning of anterior rhizoid spines, paratype USNM 154154c; 6, 7, dorsal views of two complete specimens, x 1, paratypes USNM 154154a, b; 9, interior of an attached pedicle valve, x 1, para- type USNM 154154g; 10, 11, anterior of a complete specimen, X 1, X 2, showing rhizoid spines and sleevelike flange on rim of brachial valve, paratype USNM 149259a; 13, anterior view of a complete specimen, X 3, showing needlelike spines that close off the intake tubes and the sleeve- like flange of the brachial valve, holotype USNM 124133b; 14, partial side view of an immature, attached specimen, x 1, paratype USNM 154154i; 17, ventral valve of Hercosia with window, X 1, showing attached Chonosteges within, paratype USNM 154154h; 18, dorsal view of the anterior of a complete specimen, showing a large funnel, x 3, paratype USNM 123902; 21, an- terior view of a complete specimen attached to a fenestellid funnel, X 2, paratype USNM 149259b (note unusually long rhizoid spines). [Cathedral Mountain Formation, USNM 702un.] 20, Dorsal view of a brachial valve, showing long intake funnels, X 4, paratype USNM 154155. [Cathedral Mountain Formation, USNM 726x.] NUMBER 19 1403 PLATE 243.-Chonosteges 1404 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 244 Chonosteges, Yakovlevia, Echinosteges, Paucispinifera, Oncosarina, and Xenosteges Chonosteges magnicostatus (Girty): 1, 2, Dorsal view, X 1, X 3, of the holotype USNM 118548. [Leonardian?, USGS 3880 (green).] Chonosteges pulcher, new species: 3-7, Ventral, side, dorsal, and anterior views, X 2, and dorsal view, x 1, of a paratype USNM 154157a; 8, interior, of an immature brachial valve, X 4, showing the open V-shaped cardinal process, paratype USNM 154157b; 9, 10, exterior and interior of a small brachial valve with advanced cardinal process, X 2, paratype USNM 154157c; 11-13, posterodorsal and exterior views, X 2, and dorsal view of the cardinal process, X 4, of a brachial valve, paratype USNM 154157d; 14, interior of a brachial valve, X 2, showing small brachial ridges, paratype USNM 154157g; 15-18, posterodorsal, dorsal and interior views, X 2, and posterior view, X 4, of another brachial valve, showing the complicated cardinal process and brachial ridges, paratype USNM 154157e; 19-22, interior and dorsal views of a brachial valve, X 2, and interior and dorsal views, X 2, showing thickened cardinal process, brachial ridges, intake funnels and their apertures, paratype USNM 154157f. [Cathedral Mountain Formation, USNM 721u.] Yakovlevia anterospinosa, new species: 23-26, Dorsal, anterior, ventral, and side views of a com- plete specimen, x 1, holotype USNM 154519a; 27, interior of the brachial valve, X 2, paratype USNM 154519b. [Road Canyon Formation, 732j.] Echinosteges guadalupensis (Shumard): 28, 29, Interior and exterior of a perfect brachial valve, showing an adult cardinal process, X 1, hypotype USNM 154521. [Bell Canyon Formation (Rader Member), USNM 740j.] Paucispinifera parasulcata, new species: 30, 31, Ventral and dorsal views of a complete specimen, X 1, paratype USNM 154522. [Road Canyon Formation, USNM 732j.] Oncosarina whitei (R. E. King): 32-36, Ventral, posterior, dorsal, anterior, and side views of the holotype, X 1, YPM 11685; 37, dorsal view of the holotype, x 2. [Hess Formation (Taylor Ranch Member), R. E. King 107.] Xenosteges anomalus, new species: 38-42, Anterior, side, posterior, dorsal, and ventral views of the holotype, X 2, USNM 154241a (for natural size views, see plate 234c: figures 39-41); 43, 44, posterior views of two brachial valves, x 3, showing cardinal process, paratypes USNM 154240d, e. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1405 PLATE 244,-Chonosteges, Yakovlevia, Echinosteges, Paucispinifera, Oncosarina, and Xenosteges 1406 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 245 Chonosteges Chonosteges aff. C. variabilis, new species: 1-3, Side, ventral, and anterior views of a complete specimen, X 2, figured specimen USNM 154159a; 4, 5, exterior of the brachial valve, X 1, X 2, figured specimen USNM 154159b; 6, posterior of the same brachial valve, X 3, showing cardinal process; 7, cardinal process of the preceding specimen, x 6, showing cardinal process and zygidium. [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] Chonosteges aff. C. variabilis, new species: 8, 9, Anterior and ventral views of pedicle valve, X 2, showing anterior border, figured specimen, USNM 154161. [Skinner Ranch Formation (Poplar Tank Member), USNM 707ha.] Chonosteges cf. C. variabilis, new species: 10, 11, Ventral and anterior views of an attached specimen, x 2, figured specimen USNM 154160. [Bone Spring Formation (lower), AMNH 591.] Chonosteges cf. C. variabilis, new species: 12-16, Dorsal, ventral, anterior, and side views, X 2, and dorsal view, x 1, of a complete specimen, figured specimen USNM 149264. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707b.] Chonosteges variabilis, new species: 17-20, Anterior, dorsal, and interior views, X 2, and dorsal view, X 1, of a brachial valve, showing funnel-shaped spines, paratype USNM 154158a; 21-24, dorsal view, x 1, and interior, dorsal, and anterior views, X 2, of another brachial valve having narrow anterior spines, paratype USNM 154158b; 25-28, side, anterior, ventral, and dorsal views of a complete specimen with narrow spines, x 2, paratype USNM 154384. [Cathedral Mountain Formation, 702b.] 29, Interior of a brachial valve, X 2, showing a small cardinal process, paratype USNM 154385. [Cathedral Mountain Formation, USNM 703b.] 30-33, Anterior, dorsal, side, and posterior views of a complete specimen stripped of its spines, X 2, paratype USNM 124131a. [Cathedral Mountain Formation, USNM 702.] 34-38, Side, posterior, anterior (gaping and showing inner marginal spines), ventral, and dorsal views of a complete specimen, x 2, holotype USNM 124133b. [Cathedral Mountain Formation, USNM 702un.] NUMBER 19 1407 PLATE 245.-Chonosteges *f . m <\$Y/ ma 1408 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 246 Institella and Peniculauris Institella salomonensis (Gemmellaro): 1, 2, Ventral and dorsal views of a large specimen, X 1, hypotype USNM 149167a; 3, 4, exterior and side views of a brachial valve showing strong marginal geniculation, X 1, hypotype USNM 149167b. [Sosio Formation, USNM 755.] Institella species: 5, Ventral view of a pedicle valve, X 1, figured specimen USNM 149166. Same as above. Institella leonardensis (R. E. King): 6, 7, Anterior and dorsal views, X 1, of a large sharply folded individual, hypotype USNM 123908b; 8, 9, brachial and pedicle interiors of the same specimen, x 1, hypotypes USNM 124137e, f; 10, exterior of an immature specimen, x 2, hypotype USNM 124137c; 14, exterior of a pedicle valve, showing the doubly geniculated border, X 2, hypotype USNM 124I37d. [Cathedral Mountain Formation, USNM 702.] 11, Posterior of a cardinal process, X 2, showing the myophore, hypotype USNM 123912b; 12, interior of a fragmentary brachial valve, X 2, showing dendritic adductor scars and cardinal process, hypotype USNM 123912c; 13, interior of a brachial valve, X 1, showing thickened cardinal process, median ridge and brachial ridges, hypotype USNM 123912a. [Cathedral Moun- tain Formation, USNM 702un.] Peniculauris subcostata (R. E. King): 15-19, Anterior, posterior, dorsal, side, and ventral views of a complete, young specimen, x 1, hypotype USNM 148807. [Cathedral Mountain Formation, USMN 703bs.] NUMBER 19 1409 PLATE 246.-Institella and Peniculauris 1410 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 247 Institella Institella leonardensis (R. E. King): 1, Ventral view of an attached young specimen, x 1, hypo- type USMN 149147a; 2, ventral view of a large adult attached to another individual, X 1, hypotype USNM 149147b; 3, 4, oblique and ventral views of a young individual attached to a bryozoan colony, x 1, hypotype USNM 149147c; 28, 29, oblique and ventral views of another attached specimen, X 1, hypotype USNM 149147d. [Cathedral Mountain Formation (Wedin Member), USNM 714w.] Ventral view of an immature attached specimen, x 1, hypotype USNM 149157a; 9, another immature attached specimen, x 1, hypotype USNM 149157b. [Cathedral Mountain Formation, USNM 702un.] Interior of a brachial valve distorted by crowding, x 1, hypotype USNM 154195a; 7, 8, ventral views of two immature pedicle valves, X 1, hypotypes USNM 149153a, b; 13, 31, interior and exterior of a full-grown pedicle valve, preserving its flange and some of the rhizoid spines, X 1, hypotype USNM 154195b; 14-16, dorsal, ventral, and side views of a complete specimen, preserving some of the rhizoid spines, X 1, hypotype USNM 124137c; 20, ventral view of an immature pedicle valve attached to a fragment of bryozoan, X 1, hypotype USNM 149153c; 21, interior of a large pedicle valve, X 1, showing adductor callosities and geniculated flange, hypo- type USNM 149153g; 22, another young pedicle valve attached to a bryozoan, X 1, hypotype USNM 149153d; 24, interior of a pedicle valve, X 1, hypotype USNM 154195c; 25, ventral view of a young, ungeniculated pedicle valve, X 1, hypotype USNM 149153h; 26, a young pedicle valve attached to a coral, X 1, hypotype USNM 149153c [Cathedral Mountain Formation, USNM 702b.] 10-12, Ventral, anterior, and side views of a. pedicle valve just beginning to geniculate, X 1, hypotype USNM 154196a; 17, ventral view of a pedicle valve, greatly distorted by crowding, X 1, hypotype USNM 154196b; 18, exterior of a pedicle valve with rhizoid spines, X 1, hypo- type USNM 154196i; 19, ventral view of another pedicle valve distorted by crowding, X 1, hypotype USNM 154196c; 27, dorsal view of a complete specimen distorted by crowding, X 1, hypotype USNM 152663c; 30, another pedicle valve distorted by crowding, x 1, hypotype USNM 154196d. [Cathedral Mountain Formation, USNM 721u.] 23, Ventral view of an attached adult, x 1, showing the tangled web of rhizoid spines, hypotype USNM 154197. [Cathedral Mountain Formation (Wedin Member), USNM 700x.] NUMBER 19 1411 PLATE 247.-Institella 1412 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 248 Institella Institella leonardensis (R. E. King): 1, 2, Interior of a pedicle and dorsal valve, X 1.5, showing internal pathology of the shell, hypotype USNM 154196g, h; 7, ventral exterior of a young specimen not yet geniculated, X 1, hypotype USNM 154196e; 10, side of a specimen, showing flange, X 1, hypotype USNM 154196u; 18, 19, posterior, x 15, and interior, X 1, of a brachial valve, showing expanded cardinal process, hypotype USNM 154196J; 20-22, interior, X 1, pos- terior, x 2, and exterior, x 1, views of an immature brachial valve, hypotype USNM 154196k; 23-25, exterior, interior, x 1, and posterior, x 1.5, views of a brachial valve, showing cardinal process and lateral ridges, hypotype USNM 154196-1; 26, 27, exterior and interior of another brachial valve, X 1, showing lateral and brachial ridges, hypotype USNM 154196m; 28, posterior view of a brachial valve, X 1.5, showing a narrow cardinal process, hypotype USNM 154196n; 29, ventral view of a young pedicle valve, X 1, hypotype USNM 154196o; 30, 31, posterior view of two brachial valves, showing the variable cardinal process, X 1.5, hypotypes USNM 154196p, q; 32, 33, anterior and ventral views of a large individual, x 1, showing deep flange, hypotype USNM 154196r; 34, anterior of another individual showing a broad fold, x 1, hypotype USNM 154196s; 35, 36, side and ventral views of a large specimen, x 1, showing flange, hypotype USNM 154196L [Cathedral Mountain Formation, USNM 721 u.] 3, 37, Side and anterior views of a complete specimen with angular fold, X 1, hypotype USNM 154195J; 4-6, 11, posterior, side, anterior, and ventral views, X 1, of a complete speci- men, hypotype USNM 154195d; 8, ventral view of a young pedicle valve just beginning to geniculate, X 1, hypotype USNM 154195e; 9, ventral view, X 1, of a young pedicle valve partly geniculated, hypotype USNM 154195g; 12, ventral view of a young pedicle valve in the process of geniculating, x 1, hypotype USNM 154195f; 13, 14, exterior and interior of a brachial valve, X 1, hypotype USNM 154195h, showing lobed cardinal process; 15, 16, interior and exterior of another brachial valve equal in size to the preceding but having an immature cardinal process, X 1, hypotype USNM 154195i; 38, sharply folded specimen seen in anterior view, X 1, hypotype USNM 149163a. [Cathedral Mountain Formation, USNM 702b.] 17, Side view of a gaping individual, x 1, showing the sleevelike arrangement of the flanges, hypotype USNM 154198. [Cathedral Mountain Formation, AMNH 500h.] NUMBER 19 1413 PLATE 24S.-Institella 1414 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 249 Glyptosteges Glyptosteges insculptus, new species: 1-6, Dorsal, ventral, posterior, side, and anterior views, X 1, and dorsal view, x 2, paratype USNM 152671f; 7-12, dorsal, posterior, ventral, side, and anterior views, X 1, and dorsal view, x 2, of another complete specimen, paratype USNM 152671b; 13-18, ventral, dorsal, anterior, posterior, and side views, X 1, and dorsal view, X 2, of the holotype USNM 152671c; 19-21, ventral and side views, X 1, and side view, X 2, of a specimen attached to a Composita shell, paratype USNM 154190a; 22, 23, partial side and ventral views of another attached specimen, x 1, paratype USNM 154190b; 24 dorsal view of a complete specimen, X 1, paratype USNM 154190c [Bone Spring Formation, AMNH 591.] Glyptosteges intricatus, new species: 25-28, Ventral, posterior, side, and anterior views, of a pedicle valve, x 1, paratype USNM 154191f; 29-32, ventral, side, anterior, and posterior views of a pedicle valve, x 1, paratype USNM 154191c; 57, interior of the preceding specimen, X 1.5; 42, 43, ventral and anterior views of a pedicle valve, x 1, paratype USNM 154191e; 44-48, ventral, dorsal, posterior, side, and anterior views of a complete specimen, X 1, holotype USNM 154191b (for enlarged views and interiors see plate 250: figures 29-31); 49-52, exterior, X 1, X 1.5, and posterior and interior of a brachial valve, X 1.5, showing the brachial ridges and cardinal process, paratype USNM 154191a; 53-56, posterior, interior, and exterior views, X 1.5, and exterior, X 1, of another brachial valve showing the brachial ridges, adductor scars, and ear baffles, paratype USNM 154191d; 59-61, dorsal, side, and ventral views, X 1, of an attached specimen, paratype USNM 154191g; 62, ventral view of the preceding specimen, X 2, showing rhizoid spines. [Skinner Ranch Formation (Dugout Mountain Member), USNM 732c] 33-37, Ventral, anterior, side, and posterior views, X 1, and posterointerior view of a large pedicle valve, x 1.5, showing the rhizoid spines, paratype USNM 152669; 58, interior of the preceding specimen, x 1.5, showing adductor callosity. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707g.] 38-41, Anterior side and ventral views, X 1, and ventral view of pedicle valve, X 1.5, paratype USNM 152672a. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707b.] NUMBER 19 1415 PLATE 249.-Glyptosteges 1416 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 250 Glyptosteges Glyptosteges angustus (R. E. King): 1-5, Ventral, side, posterior, X 1, and interior, X 1.5, of a pedicle valve, hypotype USNM 154192. [Skinner Ranch Formation (Sullivan Peak member), USNM 707b.] 6-10, Ventral, side, posterior, anterior, X 1, and interior, X 1.5, views of another pedicle valve, hypotype USNM 152667e; 11-15, side, posterior, anterior, and ventral views of a pedicle valve, X 1, hypotype USNM 152667g; 23, 24, posterior and interior of a brachial valve, x 1.5, showing brachial ridges, hypotype USNM 152667h. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707d.] 16, Ventral view of a pedicle valve with strong anterior ribbing, X 1.5, hypotype USNM 154193a; 17, ventral view of another pedicle valve, X 1.5, hypotype USNM 154193b; 18, 19, exterior, X 1, and interior, X 1.5, of a pedicle valve retaining some of its rhizoid spines, hypo- type USNM 154193c; 20, ventral view of a pedicle valve, X 1.5, retaining one of the curved spines of the initial attachment ring, hypotype USNM 154193d; 25, 26, exterior and interior of a brachial valve, X 1.5, showing the ear baffles, hypotype USNM 154193f; 27, 28, exterior and interior, X 1.5, of another brachial valve showing ear baffles and endospines, hypotype USNM 154193c [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] 21, 22, Interior of a brachial valve, x 1, X 2, showing brachial ridges and endospines, hypotype USNM 154194a. [Skinner Ranch Formation (Sullivan Peak Member), USNM 727a.] Glyptosteges intricatus, new species: 29-31, Interior of pedicle valve, interior of brachial valve, and dorsal view of holotype, x 2, USNM 154191b (for additional views at x 1, see plate 249: figures 44-48). [Skinner Ranch Formation (Dugout Mountain Member), USNM 732c] Glyptosteges sulcatus, new species: 32, 33, Interior and exterior of a brachial valve, x 2, holotype USNM 152674a; 34-37, ventral, side, and dorsal views, X 1, and dorsal view, X 2, of a corhplete specimen, paratype USNM 152674e; 38-40, interior, X 1, and interior and exterior, X 2, of a. brachial valve showing strong ear baffles, paratype USNM 152674f; 41, exterior of a pedicle valve distorted by crowding, X 1, paratype USNM 152674g; 42-44, anterior and ventral views, X 1, and dorsal view x 2, of a complete specimen, paratype USNM 152674c; 45, 46, exterior and interior of a brachial valve, x 2, paratype USNM 152674b. [Cathedral Mountain Formation, USNM 721u.] NUMBER 19 1417 PLATE 250.-Glyptosteges i I 1# I J '"'-hi ( i ?:? f/M^Wi- 'Mum M 27 ^4%H ^ ' .'?>. A 17 is 1418 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 251 Spyridiophora Spyridiophora compacta, new species: 1-3, Anterior, side and ventral views of a pedicle valve, X 1, paratype USNM 149312c; 4-6, anterior, posterior and side views, x 1, of the paratype USNM 149312b; 7, 8, exterior of two brachial valves, X 1, paratypes USNM 149312d, e; 9, 10, dorsal and ventral views of a complete specimen, X 1, holotype USNM 149312a. [Lenox Hills Formation, USNM 715b.] Spyridiophora reticulata (R. E. King): 11, Ventral view of a pedicle valve, X 1, hypotype USNM 154230. [Skinner Ranch Formation (Sullivan Peak Member), USNM 735f.] Spyridiophora distincta Cooper and Stehli: 12-14, Interior, side, and anterior views of an im- perfect brachial valve, X 2, showing the spyridium, paratype USNM 124116e; 15, posterior view of the preceding specimen, X 3, showing the spyridium; 16-18, interior, posterior, and side views of another brachial valve, x 2, showing lateral baffles and spyridium, holotype USNM 124117; 19, 20, posterior and interior, of the preceding specimen, x 3, showing baffles and spyridium; 21, 22, dorsal view of the holotype, x 1, and interior of the pedicle valve of the holotype, X 2; 23- 26, dorsal, x 1, and side, posterior and dorsal, x 2, views, of a complete specimen, paratype USNM 124116a; 27-31, anterior, ventral, posterior, and dorsal views, X 1, and dorsal view, X 2, of another complete specimen, paratype USNM 124116b. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701k.] NUMBER 19 1419 PLATE 25L-Spyridiophora 1420 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 252 Spyridiophora Spyridiophora reticulata (R. E. King): 1, 2, Ventral view of a young pedicle valve preserving the initial attachment ring, x 1, X 2, hypotype USNM 152665c; 3, dorsal view of an immature complete specimen, x 1, hypotype USNM 154231 j; 4-6, ventral and dorsal views, x 1, and dorsal view, X 2, showing reticulate ornament of the young stage, hypotype USNM 154231k; 7-10, dorsal, posterior, ventral, and anterior views, X 1, of a complete young specimen preserving one of its stout rhizoid spines, hypotype USNM 154231-1; 11-14, ventral, dorsal, anterior, and posterior views, X 1, of a young adult, hypotype USNM 154231m; 26-29, interior and exterior, x 1, and interior and posterior, X 2, views of a brachial valve, showing spyridium with muscle scars, hypotype USNM 154231n; 30-33, anterior, side, ventral, and posterior views of a complete specimen, x 1, hypotype USNM 15423lo; 34-37, side, anterior, posterior and ventral views of another complete specimen, X 1, hypotype USNM 152665a; 38-41, anterior, side, ventral, and posterior views of a narrow specimen, x 1, hypotype USNM 152665b. [Skinner Ranch Forma- tion (Sullivan Peak Member), USNM 722-1.] 15, Dorsal view of a brachial valve, X 1, hypotype USNM 149327. [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] 16-21, Side, dorsal, ventral, anterior, and posterior views, X 1, and dorsal view, X 2, of an imperfect specimen, hypotype USNM 149325. [Skinner Ranch Formation (top = Taylor Ranch), USNM 705r.] 22, 23, Dorsal and ventral views of a complete specimen, x 1, hypotype USNM 154233a; 24, 25, interior and exterior of a brachial valve, x 1, hypotype USNM 154233b. [Skinner Ranch Forma- tion (Poplar Tank Member), USNM 707ha.] 42^17, Dorsal, ventral, posterior, side, and anterior views, X 1, and dorsal view, X 1.5, of a complete specimen, exhibiting some of its stout rhizoid spines, hypotype USNM 149321a; 48, 49, dorsal and side views of a complete specimen preserving some of its rhizoid spines, X 1, hypotype USNM 149321b. [Hess Formation (Taylor Ranch Member), USNM 702d.] 50-54, Side, interior, posterior, and anterior views, X 2, and posterior, X 3, of a brachial valve, showing spyridium and cardinal process, hypotype USNM 124118b. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707d.] 55, Ventral view of a broken specimen, X 1, showing the spyridium, hypotype USNM 154229a; 56, 57, side and dorsal views of a complete specimen, x 1, hypotype USNM 154229b. [Bone Spring Formation, AMNH 591.] NUMBER 19 1421 PLATE 252.-Spyridiophora 1422 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 253 Spyridiophora and Glyptosteges Spyridiophora reticulata (R. E. King): 1, 2, Exterior of a brachial valve, X 2, X 1, holotype YPM 11724. [Skinner Ranch Formation (Sullivan Peak Member), R. E. King locality 4.] 3, Ventral view of an imperfect pedicle valve, x 1, paratype YPM 11727. [Skinner Ranch Forma- tion (Sullivan Peak Member), R. E. King locality 226.] , , 4-6, Posterior, anterior and ventral views of a pedicle valve, X 1, paratype T10056a; 7-9, anterior, posterior and side views of another paratype, x 1, T10056b. [Skinner Ranch Formation (upper), R. E. King locality Tb.] 11-13, Exterior and interior, X 1, and interior view, X 4, of an immature brachial valve showing spyridium, hypotype USNM 154231a; 14-16, Exterior, and interior, X 1, and interior, X 2, of another immature brachial valve, hypotype USNM 154231b; 17-19, exterior and interior, X 1, and interior, X 2, showing spyridium fusing with cardinal process, hypotype USNM 154231c; 21, interior of a brachial valve with spyridium fusing with cardinal process, X 2, hypotype USNM 154231f; 22-24, exterior and interior, x 1, and interior, x 2, view of a young brachial valve, showing cardinal process and growing spyridium, hypotype USNM 154231d; 25-27, interior, X 2, and posterior and interior, x 4, views showing fluted baffles, spyridium and cardinal process, hypo- type USNM 154231g; 28-30, exterior and interior, X 1, and interior, X 2, views of an adult brachial valve, hypotype USNM I54231e; 31-34, interior and exterior, x 1, and interior, X 2, views of an adult brachial valve, showing strong ear baffles and muscle scars on the spyridium, hypotype USNM 154231h; 35, 36, dorsal views of an immature complete specimen, X 1, X 2, hypotype USNM 15423U. [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] 20, Posterior view of a brachial valve, X 2, showing ear baffles and spyridium, hypotype USNM 154232a. [Skinner Ranch Formation (Sullivan Peak Member), USNM 727a.] Spyridiophora species 1: 37-41, Ventral, side, posterior, oblique, and anterior views of a complete specimen, x 1, YPM 12664; 42-44, posterior, oblique, and anterior views of the preceding speci- men, x 2, showing elevated fold on slope above the ear. [Said to come from Gaptank Formation (bed 3 of the Gaptank section), but the specimen contains Wolfcampian fusulinids, R. E. King locality, Sd.] Glyptosteges angustus (R. E. King): 10, Ventral view of a fragmentary pedicle valve probably referable to Glyptosteges rather than to Spyridiophora, x 1, paratype YPM 11729. [Skinner Ranch Formation (Sullivan Peak Member), R. E. King, locality 228.] NUMBER 19 1423 PLATE 253.-Spyridiophora and Glyptosteges 1424 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 254 Craspedona Craspedona newelli, new species: 1-3, Dorsal view, x 2, and ventral and dorsal views, X 1, of the holotype USNM 154172a; 4, 5, interior of a brachial valve, X 2, X 3, showing the cardinal process, zygidium, and endospines, paratype USNM 149443c; 14, interior of a brachial valve, X 1, paratype USNM 154172d; 15, exterior of a brachial valve, showing the narrow, tubelike projection at the anterior, x 1.5, paratype USNM 154172c; 16, exterior of a pedicle valve, x 2, paratype USNM 154172b; 27, interior of the pedicle valve, x 2, showing the muscle scars and elevated adductor scars, paratype USNM 154172c [Bell Canyon Formation (Hegler Member), USNM 731.] 6, 7, Interior of a brachial valve, X 3, X 1, showing brachial ridges and zygidium, paratype USNM 152664f; 8, 9, exterior and side of a siphonate brachial valve, X 2, paratype USNM 154171b; 10, side, X 1.5, of a pedicle valve; 11, anterior view of a brachial valve, X 1.5, showing the strong anterior fold, paratype USNM 154171c; 12, 13, interior, X 2, and exterior, X 1.5, of a brachial valve, showing large flange, paratype USNM 154171d; 17, exterior of a pedicle valve, X 1.5, paratype USNM 154171f; 18-21, interior and side, x 1, exterior, X 1.5, and interior X 2, of a pedicle valve showing the rhizoid spines on the posterior margin, paratype USNM 154171e; 22, interior of a pedicle valve, X 2, showing initial attachment ring and later rhizoid spines, paratype USNM 154171g; 24, 25, exterior of an attached specimen, X 2, X 1, paratype USNM 154171a. [Bell Canyon Formation (Rader Member), USNM 725f.] 23, Anterior of a complete specimen, X 2, showing siphonate projection, paratype USNM 154173. [Bell Canyon Formation (Pinery Member), AMNH 398.] 26, Exterior of a pedicle valve, X 1.5, paratype USNM 149442. [Bell Canyon Formation (Hegler Member), AMNH 625.] NUMBER 19 1425 PLATE 254,-Craspedona 1426 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 255 Agelesia Agelesia triagonalis (R. E. King): 1-3, Posterior, interior, and side views of a brachial valve, X 2, showing widely bilobed cardinal process and adductor platforms, hypotype USNM 154144a; 4-6, posterior, interior, and side views of another brachial valve, X 2, showing high median septum, hypotype USNM 154144c; 7-9, posterior, interior, and side views of a brachial valve with unusu- ally well developed median septum, X 2, hypotype USNM 154144b; 17, dorsal view of a complete specimen, X 1, showing anchor spines, hypotype USNM 154144d; 22, ventral view of an attached specimen, x 1, hypotype USNM 154144g; 27, 28, ventral view of another attached specimen, x 1, X 2, showing long rhizoid spines, hypotype USNM 154144J; 34, specimen in ventral view attached to a branch of a bryozoan, x 1, hypotype USNM 154144L [Cathedral Mountain Formation (Wedin Member), USNM 723u.] 10-12, Side, dorsal, and ventral views of a specimen stripped of its spines, X 1, hypotype USNM 154145a; 13, 14, interior of a brachial valve, X 1, X 2, hypotype USNM 154145b; 15, 16, interior of another brachial valve, X 1, X 2; hypotype USNM 154145c [Cathedral Mountain Formation, USNM, 721u.] 18, 19, Two dorsal views of a small cluster of specimens attached to Enteletes, X 1, hypotype USNM 154146a; 30, 31, side and ventral views of another specimen attached to Enteletes, X 1, hypotype USNM 154146b; 32, small individual attached to Institella, x 1, hypotype USNM 154146c; 40-43, dorsal view, x 1, and ventral, side and dorsal views, X 2, showing the long rhizoid spines, hypotype USNM 154146d. [Cathedral Mountain Formation (Wedin Member), USNM 714w.] Posteroventral view of a specimen with umbonal region removed to show the adductor plat- forms within, X 1, hypotype USNM 153834a; 25, 26, dorsal and ventral views of an attached specimen, x 1, hypotype USNM 153834b; 29, interior of a pedicle valve; X 1, hypotype USNM 153834c; 35-39, side, anterior, posterior, dorsal, and ventral views of a complete specimen, X 1, hypotype USNM 153834d; 44, ventral view of specimen, x 1, showing the long rhizoid spines, hypotype USNM 153834g. [Cathedral Mountain Formation, USNM 703bs.] Dorsal view of a specimen attached to Institella, X 1, hypotype USNM 154147a; 33, small individual attached to Institella, x 1, hypotype USNM 154147b. [Cathedral Mountain Formation (Wedin Member), USNM 727p.] 23, 24, Dorsal and side views of a specimen attached to a fenestellid frond, X 1, hypotype USNM 154148. [Cathedral Mountain Formation (Wedin Member), USNM 700-1.] NUMBER 19 1427 PLATE 255,-Agelesia 1428 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 256 Ametoria and Ramavectus Ametoria residua, new species: 1-3, Exterior and interior, X 1, and posterior, X 2, views of a brachial valve, showing the cardinal process and median ridge, paratype USNM 149364a; 7-10, ventral, anterior, side, and posterior views of the holotype, X 1, USNM 153476; 11-13, Interior, side, and exterior views of a brachial valve, X 1, paratype USNM 149364b; 14, interior of another brachial valve, X 2, paratype USNM 149364c [Road Canyon Formation, USNM 703d.] 4-6, Side, posterior, and ventral views of a large pedicle valve, X 1, paratype USNM 154029. [Road Canyon Formation, AMNH 503.] Ramavectus diabloensis Stehli: 15, 16, Side and ventral views of a pedicle valve, X 1, hypotype USNM 154210b; 17-19, ventral, interior, and posterior views of another pedicle valve, X 1, hypo- type USNM 154210a; 20-22, fragments of three brachial valves, X 1, showing the divergent struts anterior to the cardinal process, hypotypes USNM 154210J, h, f; 23, 24, exterior and interior of the brachial valve, X 1, hypotype USNM 154210k. [Bone Spring Formation, USNM 728c] NUMBER 19 1429 PLATE 256.-Ametoria and Ramavectus 1430 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 257 Limbella and Ramavectus Limbella limbata, new species: 1, 2, Ventral view, X 1, X 2, of a young specimen retaining its initial attachment rings, paratype USNM 154211, [Skinner Ranch Formation (Sullivan Peak Mem- ber), USNM 722-1.] Ramavectus diabloensis Stehli: 3, 4, Ventral and interior views, X 1, of a small pedicle valve, hypotype USNM 149450b; 5, 6, exterior and interior of a young brachial valve, X 1, hypotype USNM 149450a; 17-19, posterior, side, and ventral views of a large pedicle valve, X 1, hypotype USNM 148959a; 20, 21, interior and ventral views of another pedicle valve, X 1, showing the short interarea, hypotype USNM 148959b. [Bone Spring Formation, AMNH 625.] 7-10, Interior, side, ventral, and anterior views of a young pedicle valve, X 1, showing an inter- area, hypotype USNM 148957b; 11-14, exterior, side, and interior views, X 1, and posterior of the cardinal process, X 2, of a large brachial valve, hypotype USNM 148957a; 15, ventral view of a large pedicle valve, X 1, hypotype USNM 154210c; 16, interior of a brachial valve, showing the struts anterior to the cardinal process, X 1, hypotype USNM 154210d. [Bone Spring Formation, USNM 728e.l NUMBER 19 1431 PLATE 257.-Limbella and Ramavectus 1432 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 258 Rhamnaria, Ramavectus, and Echinosteges Rhamnaria eximia, new species: 1-4, Posterior, ventral, side, and interior views of the pedicle valve, X 1, paratype USNM 149451c; 5, 6, interior and exterior of a young brachial valve, X 1, paratype USNM 149451g; 7-10, interior, posterolateral, exterior, and side views of a full-grown brachial valve, X 1, paratype USNM 149451e; 11-14, side, posterior, anterior, and ventral views of a large pedicle valve, x 1, paratype USNM 149451b; 15-18, side, interior, posterodorsal, and exterior views of a brachial valve, X 1, paratype USNM 149451d; 19-22, ventral, anterior, posterior, and dorsal views of another large pedicle valve, X 1, holotype USNM 149451a; 23, 24, exterior and interior of a young brachial valve, x 1, paratype USNM 149451 h; 25, 26, exterior and interior of another brachial valve, x 1, paratype USNM 149451f. [Bone Spring Formation, USNM 728f.] Ramavectus diabloensis Stehli: 27-29, Posterior, side, and ventral views of an imperfect pedicle valve, X 1, hypotype USNM 154210-1. [Bone Spring Formation, USNM 728c] Echinosteges guadalupensis (Shumard): 30, Posterior view of a hypotype, showing the interarea and elytridium, x 2, USNM 152652a (for additional views see plate 229: figures 10-12). [Bell Canyon Formation (Rader Member), USNM 725f.] Echinosteges, species: 31, 32, Posterior and ventral views, showing numerous slender ornament spines, X 1, figured specimen USNM 149045. [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] NUMBER 19 1433 PLATE 258.-Rhamnaria, Ramavectus, and Echinosteges rim f'f ^ -* #*?¯.. '?^W*j m ^< " ? -r-'fM/,'- it,. . -. aP*p&* It Ik 1434 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 259 Rhamnaria Rhamnaria tenuispinosa, new species: 1, 2, Ventral and dorsal views of a specimen preserving most of its spines, X 1, paratype USNM 154215f; 6, dorsal view of a young spiny specimen, X 1, paratype USNM 154215J; 7-9, dorsal, interior, and side views of a brachial valve, X 1, paratype USNM 154215d (for exterior views of the whole specimen, see plate 260: figures 24-26); 10-12, dorsal, interior, and side views of another brachial valve, x 1, paratype USNM 154215h; 25, ex- terior of a pedicle valve with long ornament spines, X 1, paratype USNM 154215L [Road Canyon Formation (base), USNM 702c] 33, Interior and exterior of a pedicle valve, x 1, paratype USNM 154219b. [Cathedral Moun- tain Formation, USNM 721u.] 5, Ventral and dorsal views of a young specimen attached to a bryozoan, x 1, paratype USNM 154217d; 17-19, dorsal, ventral, and anterior views of a complete but young adult, x 1, paratype USNM 149360g; 23, 24, exterior, X 1, and interior, X 2, of a pedicle valve, showing initial attach- ment, ring, paratype USNM 154217e; 29, 30, dorsal and ventral views of a complete young specimen, showing the initial ring of attachment, x 1, paratype USNM 149360h. [Cathedral Mountain For- mation, USNM 702un.] 13-16, Ventral, anterior, posterior, and side views of a large pedicle valve, X 1, paratype USNM 149373c; 20, interior of a large brachial valve, x 1, paratype USNM 149373d; 26, ventral view of a pedicle valve, x 1, paratype USNM 149373g; 27, 28, exteriors of two ventral valves, X 1, showing delicate ornament spines, paratypes USNM 149373e, f. [Cathedral Mountain Formation, USNM 703a1.] 21, 22, Exterior and interior of a brachial valve, X 1, paratype USNM 154216h; 31, 32, interior and exterior of another brachial valve, x 1, showing a deformed cardinal process, paratype USNM 154216L [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1435 PLATE 259.-Rhamnaria HakPi W^9l ?r ? ' ? - ^^jA3 fill 30 1436 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 260 Rhamnaria Rhamnaria tenuispinosa, new species: 1, 2, Dorsal and posterior views of a complete specimen, x 1, paratype USNM 149357a; 10-13, side, anterior, posterior, and interior views of a large pedicle value, X 1, showing adductor track, paratype USNM 149357b; 16, 17, interior and posterior of a brachial valve, x 1, showing the cardinal process, paratype USNM 154216g. [Cathedral Mountain Formation, USNM 702.] 3-6, Anterior, side, dorsal, and ventral views of a small adult, x 1, paratype USNM 154215b; 9, interior of a brachial valve, X 1, paratype USNM 154215c; 20-23, side, dorsal, anterior, and ventral views, X 1, of the holotype USNM 149359a; 24-26, posterior, dorsal, and ventral views of a com- plete specimen preserving some of its rhizoid spines, X 1, paratype USNM 154215d (for dorsal interior of this specimen see plate 259: figures 7-9); 27, 28, side and ventral views of another speci- men preserving many of its spines, x 1, paratype USNM 154215c [Road Canyon Formation (base), USNM 702c] 7, 8, Interior and dorsal views of a brachial valve, x 1, paratype USNM 154218a; 14, 15, side and interior of another large brachial valve, x 1, paratype USNM 154218b. [Cathedral Mountain For- mation, USNM 702b.] 18, 19, Exterior and interior of a large brachial valve, X 1, showing thickened cardinal process and breviseptum, paratype USNM 149373b. [Cathedral Mountain Formation, USNM 703a1.] NUMBER 19 1437 PLATE 260.-Rhamnaria 1438 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 261 Rhamnaria Rhamnaria rectangulata, new species: 1-8, Dorsal, interior, and side views of the brachial valve, X 1, and posterior, ventral, anterior, dorsal, and side views of the ventral valve of the same speci- men, x 1, holotype USNM 149409a; 9-15, side, dorsal, and interior views, X 1, of the brachial valve and dorsal, interior, anterior, and ventral views, X 1, of the complete specimen, paratype USNM 149409b. [Road Canyon Formation, USNM 703d.] Rhamnaria tenuispinosa, new species: 16-19, Ventral, dorsal, anterior, and side views of a small adult, x 1, paratype USNM 154215a. [Road Canyon Formation (base), USNM 702c] 20-22, Dorsal, anterior, and ventral views of a small individual, X 1, paratype USNM 149360c; 29, dorsal view of a young attached specimen, x 1, paratype USNM 154217a; 31, 32, dorsal and ventral views of a specimen attached to a bryozoan, x 1, paratype USNM 154217b; 35-37, side, ventral, and dorsal views of an attached specimen, showing deformation due to crowding against the bryozoan branches, x 1, paratype USNM 154217c [Cathedral Mountain Formation, USNM 702un.] , 23, 24, Ventral and dorsal views of an immature specimen, x 1, paratype USNM 154216a; 25, 26, dorsal and ventral views of a small attached specimen, x 1, paratype USNM 154216b; 30, dorsal view of another immature complete specimen, X 1, paratype USNM 154216c; 38, 39, ventral and dorsal views of an immature specimen, x 1, paratype USNM 154216f; 40, 41, ventral and side views of attached adult, X 1, paratype USNM 149356. [Cathedral Mountain Formation, USNM 702.] 33, 34, Dorsal, X 1, and side, X 2, views of a specimen attached to a sponge fragment and show- ing the rhizoid spines coming off all parts of the pedicle valve, paratype USNM 149373a. [Cathedral Mountain Formation, USNM 703a1.] 27, 28, Interior of an immature pedicle valve, X 1, X2, showing the short median septum, para- type USNM 154531. [Cathedral Mountain Formation, USNM 702a.] NUMBER 19 1439 PLATE 261.-Rhamnaria ' '¯*?", ???. ." i ' 10 ~'n ®HI 3 *^l$fe- 1440 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 262 Rhamnaria Rhamnaria tenuispinosa, new species: 1, Dorsal view of an exceptionally large specimen, X 1, paratype USNM 154220. [Cathedral Mountain Formation, USNM 726o.] Rhamnaria sulcata, new species: 2, 3, Interior and exterior of an immature brachial valve, X 1, paratype USNM 149402x; 4-7, ventral, posterior, side, and anterior views of a young adult, X 1, paratype USNM 149402g; 8-11, ventral, side, posterior, and anterior views of a small adult, X 1, paratype USNM 149402e; 12, interior of an immature pedicle valve, x 1, paratype USNM 149402q; 13, 14, exterior and interior of a young brachial valve, X 1, paratype USNM 149402u; 15-18, ventral, posterior, anterior, and side views of a young pedicle valve, X 1, paratype USNM 149402h; 19-21, interior, exterior, and posterodorsal views of a small brachial valve with widely bilobed cardinal process, X 1, paratype USNM 149402v; 22-24, side, exterior, and interior of a brachial valve with normal cardinal process process, X 1, paratype USNM 149402w; 25-27, interior, side, and exterior views of a large brachial valve with thickened cardinal process, X 1, paratype USNM 149402J; 28-30, exterior, side, and interior of another brachial valve, x 1, paratype USNM 149402s; 31-34, interior, exterior, side, and posterodorsal views of a brachial valve, showing a bilobed cardinal process, X 1, paratype USNM 149402t; 35-38, posterior, anterior, ventral, and side views of a young, complete adult, x 1, paratype USNM 149402c; 39-42, interior, side, postero- dorsal, and exterior views of a large brachial valve having a cardinal process in a juvenile stage, X 1, paratype USNM 149402r; 43-46, posterior, anterior, side, and ventral views of a large pedicle valve, x 1, paratype 149402p; 47-50, ventral, side, anterior, and posterior views of a large pedicle valve, showing the strong median sulcus, x 1, holotype USNM 149402a. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1441 PLATE 262.-Rhamnaria 9 38 ^4B 49 50 1442 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 263 Rhamnaria Rhamnaria kingorum delicata, new subspecies: 1-4, ventral, anterior, dorsal, and side views of complete adult, x 1, paratype USNM 154221b; 5-8, ventral, posterior, side, and dorsal views of a large adult, x 1, holotype USNM 154221a; 9, 10, dorsal and ventral views of a rounded specimen, X 1, paratype USNM 149396c; 11-13, ventral, dorsal, and side views of an immature individual, X 1, paratype USNM 149396f; 14, interior of an immature pedicle valve, X 1, showing median septum, paratype USNM 154221 h; 15, interior of an immature brachial valve distorted by crowd- ing, X 1, paratype USNM 154221 f; 16-18, ventral, dorsal, and side views of a young specimen, X 1, paratype USNM 149396i; 21-23, ventral, dorsal, and side views of a young adult, X 1, paratype USNM 149396h; 26-28, ventral, side, and dorsal views of a specimen elongated by crowding, x 1, paratype USNM 149396J; 29, ventral view of an adult preserving some of its rhizoid spines, X 1, paratype USNM 154221m; 30, 31, two brachial valve interiors, X 1, showing different development of the cardinal process, paratypes USNM 154221e, i; 32, interior of an immature pedicle valve, showing the median septum, X 1, paratype USNM 154221o; 33-35, interior of three brachial valves, X 1, showing variation of the interior, paratypes USNM 154221d, k, 1; 36, ventral view of a pedicle valve preserving the initial attachment ring, X 1, paratype USNM 154221n; 37, ventral view of a young individual with rhizoid spines, x 1, paratype USNM 154221q; 40, 41, interior of two brachial valves, X 1, showing variation in cardinal process, paratypes USNM 154221J, c; 42^4, side and interior views, X 1, and interior view, showing the median septum, X 2, of an immature pedicle valve attached to Paucispinifera, paratype USNM 149396k; 45, 46, ventral and side views of a specimen attached to Costispinifera, x 1, showing the numerous fine rhizoid spines, paratype USNM 149396-1; 47, interior, X 1, of an immature brachial valve, paratype USNM 154221g; 48, 49, dorsal view of an immature pedicle valve, x 1, X 2, showing the median septum, paratype USNM 149396m. [Word Formation (China Tank Member), USNM 706c] 19, 20, Exterior and interior of a young brachial valve, x 1, paratype USNM 154222b; 24, 25, interior and exterior of a young pedicle valve, x 1, paratype USNM 154222a. [Word Formation (China Tank Member), USNM 726r.] 38, 39, Oblique and ventral views, X 1, of a specimen attached to the pedicle valve of Megousia, paratype USNM 154223. [Word Formation (China Tank Member), USNM 733q.] NUMBER 19 1443 PLATE 26S.-Rhamnaria 1444 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 264 Rhamnaria Rhamnaria kingorum Muir-Wood and Cooper: 1, 2, Ventral and dorsal views of a young speci- men attached to a bryozoan, x 1, hypotype USNM 149389a; 3, dorsal view of a young specimen occupied by a number of other young brachiopods, x 1, hypotype USNM 149389b; 4, ventral view of a young pedicle valve with ornament and rhizoid spines, x 1, paratype USNM 124072p; 7, 8, interior of a pedicle valve, X 2, X 1, showing muscle scars and initial attachment ring clasp- ing a crinoid stem, paratype USNM 124072a: 10, posterior of a pedicle valve showing the cicatrix of attachment, X 2, paratype USNM 124072c; 11, ventral view of a pedicle valve, X 1, showing some of its rhizoid spines, hypotype USNM 154213k; 12, exterior of a young ventral valve, X 1, hypotype USNM 149389c; 13, exterior of another, younger pedicle valve, X 1, paratype USNM 124072o; 14, 15, interior and exterior of a pedicle valve distorted by crowding, X 2, paratype USNM 124072k; 16, exterior of a ventral valve, x 1, showing its rhizoid spines, hypotype USNM 154213-1; 17, 18, ventral and side views of a pedicle valve attached to a pelecypod shell, X 1, hypotype USNM 149389d; 19, 20, oblique view of a pedicle valve, X 1, X 2, showing the numerous ornament spines, paratype USNM 124072e; 21, ventral view of a complete specimen, X 1.5, X 1, showing mode of attachment, paratype USNM 124072m; 22, immature specimen deformed by growing against transverse spines over the dorsal exterior of a dorsal valve of Echinauris, X 2, hypotype USNM 149697; 25, interior of an immature pedicle valve, X 1, showing its median septum, hypotype USNM 154213u; 26, interior of another immature pedicle valve, X 1, attached to the brachial valve of Echinauris, and showing the median septum, hypotype USNM 154213s; 27, interior of a young brachial valve, X 1, hypotype 154214f; 28, ventral view of a small attached pedicle valve, X 1, hypotype USNM 149389e; 29, ventral view of an adult pedicle valve, X 2, attached to Paucispinifera and showing the role of the rhizoid spines, paratype USNM 124072f. [Word Formation (Willis Ranch Member), USNM 706c] 5, 6, Exterior, X 1, and interior, X 2, of a pedicle valve preserving the initial attachment ring, hypotype USNM 149388a; 9, interior of an immature brachial valve, X 1, hypotype USNM 154214e; 23, 24, interior, X 1, X 2, of a pedicle valve attached to a brachial valve and showing the median septum, hypotype USNM 149388b. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1445 PLATE 264.-Rhamnaria 1446 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 265 Rhamnaria Rhamnaria kingorum Muir-Wood and Cooper: 1-5, Dorsal, ventral, posterior, side, and anterior views of an immature individual, X 1, hypotype USNM 149383i; 6-10, ventral, anterior, posterior, side, and dorsal views of another immature specimen, older than the preceding, X 1, hypotype USNM 149383h; 11-15, ventral, side, dorsal, anterior, and posterior views of a still larger specimen than the preceding, x 1, hypotype USNM 149383g; 16, interior of an immature brachial valve, X 1, hypotype USNM 154214g; 17-21, dorsal, ventral, posterior, anterior, and side views of an- other complete, nearly adult specimen, x 1, hypotype USNM 149383f; 22, interior of another immature brachial valve, X 1, hypotype USNM 154214h; 23, 24, interior of two half-grown brachial valves, X 1, hypotypes USNM 154214i, j; 35-37, dorsal, side, and interior views of an adult brachial valve, x 1, hypotype USNM 154214k; 38, 39, dorsal and ventral views of a large adult, X 1, hypotype USNM 149383d; 40-42, interior, side, and dorsal views of a large brachial valve with strongly lobed cardinal process, X 1, hypotype USNM 154214-1; 43, 44, side and dorsal views of a large complete specimen, x 1, hypotype USNM 149383b; 45-49, side, posterior, interior, anterior and ventral views of a large pedicle valve, X 1, showing muscle scars, hypotype USNM 149383J. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] 25, 26, Interior and side views of a young brachial valve, X 1, hypotype USNM 154213i; 27, 28, interior and side views of another brachial valve more highly developed cardinal process than the preceding specimen, x 1, hypotype USNM 154213J; 29-31, side, dorsal, and interior views of a large brachial valve, X 1, hypotype USNM 154213e; 32-34, dorsal, side, and interior views of an- other brachial valve, X 1, hypotype USNM 154213h. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1447 PLATE 265.-Rhamnaria 1448 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 266 Rhamnaria Rhamnaria kingorum Muir-Wood and Cooper: 1, Interior of a brachial valve, X 2, showing endospines, breviseptum and cardinal process, paratype 124072J; 2-5, ventral, anterior, side, and posterior views of a pedicle valve, X 1, holotype USNM 124072b; 6, 7, posterior and interior views of a brachial valve with widely bilobed cardinal process, X 1, hypotype USNM 154213a; 11, 12, interior of a small but obese brachial valve, X 2, X 1, hypotype USNM 124072q; 15, interior of a brachial valve, X 2, showing endospines, dendritic adductor scars, and cardinal process, paratype USNM 124072i; 18, ventral view of a pedicle valve X 2, showing its mode of attachment, paratype USNM 124072d; 19, 20, interior and posterior of a young brachial valve, X 2, showing the immature cardinal process, paratype USNM 124072-1; 21-23, exterior and interior, X 2, and interior, X 1, of an obese brachial valve with greatly expanded cardinal process, paratype USNM 124072h. [Word Formation (Willis Ranch Member), USNM 706c] 8-10, Side and exterior, X 1, and exterior, X 2, showing numerous spines on the brachial valve, hypotype USNM 154214a; 13, 14, interior and exterior of a young brachial valve X 1, showing excessive growth of the cardinal process, hypotype USNM 154214c; 16, 17, interior and side views of a brachial valve, x 1, hypotype USNM 154214d. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1449 PLATE 266.-Rhamnaria ?: y'. ?: 1450 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 267 Echinosteges and Rhamnaria Echinosteges guadalupensis (Shumard): 1-4, Side, ventral, anterior, and dorsal views of a complete specimen, x 1, hypotype USNM 154523, [Capitan Formation, USNM 738a.] Rhamnaria shumardi, new species: 5-8, Ventral, side, dorsal, and anterior views of a small speci- men, X 1, paratype USNM 149408k; 9-12, ventral, dorsal, anterior, and side views of a complete specimen, x 1, holotype USNM 149408c; 13-16, posterior, ventral, anterior, and side views of a pedicle valve, X 1, paratype USNM 149408b. [Capitan Formation, USNM 738a.] 17, 18, Side and ventral views of a silicified pedicle valve, X 1, paratype USNM 149406. [Bell Canyon Formation (Pinery Member), USNM 733.] 19, 20, Interior of two immature brachial valves, X 1, paratypes USNM 154212a, b. [Bell Canyon Formation (post-Rader Limestone), AMNH 409.] Rhamnaria grandis new species: 21-24, Side, ventral, anterior, and dorsal views of a large com- plete specimen, X 1, holotype USNM 149380a. [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] NUMBER 19 1451 PLATE 267.-Echinosteges and Rhamnaria "v.v-'.. V&sr. 1452 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 268 Tschernyschewia Tschernyschewia americana, new species: 1, 2, Interior and oblique views of a pedicle valve, X 2, showing the strong, long median septum, holotype USNM 152683c; 3-5, posterior, exterior, and interior views of a brachial valve, X 2, showing the bilobed cardinal process, paratype USNM 152683a; 6-8, posterior, interior, and exterior of another brachial valve larger than the preceding, X 2, paratype USNM 152683b; 9-14, posterior, anterior, side, ventral, and dorsal views, X 1.5, and dorsal view, X 1, of a complete specimen, paratype USNM 149434c; 15-20, side, ventral, posterior, anterior, and dorsal views, X 1.5, and dorsal view, x 1, of another complete specimen, paratype USNM 149434b; 21, 22, dorsal view of a specimen attached to the substrate, x 1, X 2, paratype 149434d. [Bone Spring Formation, AMNH 591.] Tschernyschewia inexpectans, new species: 23, Interior of a fragmentary brachial valve, showing the divergent prongs of the cardinal process, X I, paratype USNM 154234. [Hess Formation (Taylor Ranch Member), USNM 702d.] 24-27, Side, dorsal, posterior, and ventral views of a complete specimen, x 1, paratype USNM 152682b; 28-31, posterior, side, dorsal, and ventral views of another complete specimen, X 1, paratype USNM 152682a; 32, ventral view of a pedicle valve, x 1, paratype USNM 152682d. [Hess Formation (Taylor Ranch Member), USNM 716n.] 33-36, Dorsal, posterior, and side views, x 1, and dorsal view x 1.5, of a complete specimen, holotype USNM 152681; 37, 38, oblique anterior and anterior views of the holotype, X 1, show- ing the median septum of the pedicle valve; 39, oblique anterior view of the holotype, X 1.5, showing the median septum of the pedicle valve. [Hess Formation (Taylor Ranch Member), USNM 716o.] NUMBER 19 1453 PLATE 268.-Tschernyschewia *>?&??.. rS* ##^ 12 -f^19 j *& 20 1454 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 269 Tschernyschewia and Strophalosia Tschernyschewia species: 1-3, Ventral, side, and interior views of a pedicle valve, X 1, showing the median septum and rhizoid spines on the body of the shell, figured specimen USNM 149359a; 4-6, exterior, side, and interior of a fragmentary brachial valve, X 1, figured specimen USNM 149359b; 7, interior of a large brachial valve, X 1, showing a trace of the pedicle valve median septum between the prongs of the cardinal process, figured specimen 149359c [Road Canyon Formation (base), USNM 702c] 8-10, Ventral, side, and interior views of a large pedicle valve, X 1, figured specimen USNM 152684a; 11, 12, interior and exterior of a fragment of the brachial valve showing the cardinal process, X 1, figured specimen USNM 152684b. [Road Canyon Formation, USNM 719x.] Strophalosia inexpectans, new species: 13-16, Ventral, anterior, posterior, and side views of a pedicle valve, X 1, paratype USNM 151229a; 17-21, anterior, posterior, ventral, side, and interior views of a pedicle valve, x 1, holotype USNM. 151229b; 22, interior of the holotype, X 2, show- ing muscle scars; 23, interarea of the holotype, X 3, showing teeth and flat pseudodeltidium; 24, interarea of another specimen, X 2, showing the teeth and pseudodeltidium, paratype USNM 151229c; 25, 26, interior and exterior of a brachial valve, x 1, paratype USNM 151229d; 27-30, posterior, posterodorsal, interior, and oblique views of the preceding brachial valve X 3, show- ing the cardinal process, sockets and myophore. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1455 PLATE 269.-Tschernyschewia and Strophalosia 1456 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 270 Scacchinella Scacchinella primitiva, new species: 1-3, Posterior, ventral, and side views of a large pedicle valve, X 1, paratype USNM 151701b; 4, interior of an imperfect pedicle valve, X 1, showing "brachial ridges," paratype USNM 151701J; 5-7, posterior, side, and ventral views of a pedicle valve pre- serving the beak, X 1, paratype USNM 151701c; 8, 9, apical and side views of a specimen shorn of the beak, X 1, paratype USNM 151701g; 10, interior impression of the brachial valve, X 1, showing the adductor ridges and "brachial ridges," holotype USNM 151701a; 11, partial side view of the holotype, showing the median septum and one prong of the cardinal process, X 1. [Gaptank Formation, USNM 700g.] Scacchinella titan, new species: 12, Polished section of a pedicle valve, showing the long median septum, and crisscross plates that strengthen the conical pedicle valve, X 1, paratype USNM 147934. [Skinner Ranch Formation (Decie Ranch Member), USNM 707w.] 13, Tilted posterior view of a brachial valve, showing one prong of the cardinal process with its deep myophore at the distal end, x 2, paratype USNM 153665d; 14, 15, apical and posterior views of a young, wide specimen, showing attachment cicatrix and rhizoid spines, X 1, paratype USNM 153665e; 16, ventral view of the preceding specimen, x 2, showing some of the rhizoid or attachment spines. [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1457 PLATE 270.-Scacchinella 1458 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 271 Scacchinella Scacchinella triangulata, new species: 1, Polished surface of a cross section of the pedicle valve, showing septum, X 1, paratype USNM 153669a; 10, interior of a specimen from which the ventral side has been stripped, X 1, showing the median septum and the forked cardinal process, paratype USNM 153669b. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 702n.] 2-5, Ventral, side, posterior, and dorsal views of a small adult, X 1, paratype USNM 151694b; 6-9, ventral, dorsal, posterior, and side views of a large individual, X 1, holotype USNM 151694a. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 702q.] 11, Exterior of a very large brachial valve, X 1, paratype USNM 151697b; 12, posterior view of a complete specimen, x 1, showing the median septum and the cardinal process, paratype USNM 151697a. [Gaptank Formation (Uddenitew-bearing Shale Member), USNM 702r.] 13, Interior of a brachial valve, X 1, showing the forked cardinal process and large adductor impressions, paratype USNM 151691a. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 701q.] Scacchinella exasperata, new species: 14-16, Dorsal, side, and posterior views of a young speci- men, X 1, paratype USNM 151686g; 17-19, dorsal, side, and posterior views of a larger specimen than the preceding, X 1, paratype USNM 151686c; 20-22, ventral, side, and posterior views of a large individual, X 1, holotype USNM 151686a; 23, posterior view of a specimen from which the shell has been stripped to show the median septum and cardinal process, X 1, paratype USNM 151686J; 24, polished section of a pedicle valve, X 1, showing the strong median septum, paratype USNM 151686k. [Lenox Hills Formation, USNM 705k.] NUMBER 19 1459 PLATE 271.-Scacchinella 1460 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 272 Scacchinella Scacchinella titan, new species: 1-4, Ventral, posterior, side, and dorsal views of a complete speci- men, x 1, paratype USNM 153670a; 5, 6, side and ventral views of an elongated specimen, X 1, paratype USNM 153670b. [Skinner Ranch Formation, USNM 724p.] Scacchinella americana Stehli: 7-9, Brachial valve tilted to show cardinal process, interior, and side views, also showing elevated adductor scar attachments, X 1, hypotype USNM 153671. [Bone Spring Formation (lower), USNM 725c] 10-13, Interior, interior tilted, side, and posterior views of another brachial valve, showing the cardinal process, X 1, hypotype USNM 153672a; 14-16, ventral, interior, and side views of the pedicle valve, showing the median septum, X 1, hypotype USNM 153672b. [Bone Spring Forma- tion (lower), USNM 728c] 17-20, Posterior, ventral, side, and dorsal views of a complete specimen, x 1, hypotype USNM 148031a; 21-23, side, posterior, and dorsal views of a short specimen, X 1, hypotype USNM 148031c [Bone Spring Formation, AMNH 699.] 24-27, Side, dorsal, posterior, and ventral views of a stout specimen, x 1, hypotype USNM 148034. [Bone Spring Formation, AMNH 655.] NUMBER 19 1461 PLATE 272.-Scacchinella i ? ? , 1462 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 273 Scacchinella Scacchinella titan, new species: 1, Side view of a small pedicle valve covered by rhizoid spines, X 1, figured specimen USNM 151799s; 2, interior of a small brachial valve, X 1, figured speci- men USNM 151799k; 3, interior of a small pedicle valve, X 2, figured specimen USNM 151799-1; 4-7, dorsal, posterior, ventral, and side views of a complete specimen, x 1, figured specimen USNM 151799e; 8, interior of a small brachial valve, X 1, figured specimen USNM 151799m; 9, 10, posterior and ventral views of a pedicle valve, showing the distal end of the median septum, X 1, figured specimen USNM 151799b; 11, small specimen attached within another shell, X 2, figured specimen USNM 151799n; 12, 13, posterior and ventral views of a fragmentary dorsal valve, showing cardinal process and myophores, X 2, figured specimen USNM 151799r; 14, 15, posterior and ventral views of a pedicle valve preserving many of the attachment spines, X 1, figured specimen USNM 151799c; 16-19, dorsal, posterior, side, and ventral views of a well formed individual, X 1, figured specimen USNM 151799d; 20, broken specimen, X 1, showing median septum, figured specimen USNM 151799p; 21, interior of the brachial valve belonging to the preceding specimen, X 1; 22, interior of a small pedicle valve, X 1, showing the distal end of the median septum, figured specimen USNM 151799q; 23, 24, side and posterior views of a large specimen, X 1, showing the median septum and broad interarea, figured specimen USNM 151799a; 25, interior of a brachial valve, X 1, showing "brachial ridges," figured specimen USNM 1517990. [Cibolo Formation (Breccia Zone), AMNH 703.] Scacchinella exasperata, new species: 26-28, Posterior, ventral, and side views of a large, com- plete specimen, x 1, paratype USNM 151686b. [Lenox Hills Formation, USNM 705k.] NUMBER 19 1463 PLATE 27 ^.-Scacchinella 1464 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 274 Scacchinella Scacchinella titan, new species: 1, Dorsal view of a large specimen, showing the rounded convex brachial valve that forms a lid on the conical pedicle valve, X 1, paratype USNM 147982b (for additional views of this specimen, see plate 276: figures 1-3); 2, 3, posterior and dorsal views of an unusually large fragmentary specimen, x 1, paratype USNM 147978; 4, exterior of a large but decorticated brachial valve, X 1, paratype USNM 147982m. [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] 5, Exterior of a silicified brachial valve, X 1, paratype USNM 124180; 6, exterior of the preceding specimen, x 2, showing some of the fine spines that originally covered the entire surface. [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1465 PLATE 274.-Scacchinella 1466 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 275 Scacchinella Scacchinella titan, new species: 1-3, Side, posterior, and ventral views of a large individual, showing the irregular plates filling the pedicle valve, X 1, paratype USNM 147982c; 4, posterior view of the largest specimen, x 0.5, paratype USNM 147982a. [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] NUMBER 19 1467 PLATE 27b.-Scacchinella 1468 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 276 Scacchinella Scacchinella titan, new species: 1-3, Ventral, posterior, and side views of one of the largest specimens, X 1, paratype USNM 147982b (for the dorsal view of this specimen, see plate 274: figure 1). [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] NUMBER 19 1469 PLATE 27^.-Scacchinella .fTTv ^..J>ff$-- t-X^wi^?S^tfe&fti ¯-"?? i '.-.1 U- a 1470 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 277 Scacchinella Scacchinella titan, new species: 1-4, Side, dorsal, posterior, and ventral views of a large but short specimen, x 1, paratype USNM 147973. [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] Scacchinella species: 5, Posterior part of the brachial valve of a badly worn, possibly reworked specimen, x 1, figured specimen USNM 153663. [Cathedral Mountain Formation, USNM 721u.] NUMBER 19 1471 PLATE 277.-Scacchinella J472 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 278 Scacchinella Scacchinella titan, new species: 1, 2, Ventral and posterior views of a slender, young individual, X 1, paratype USNM 153661b; 3, 4, ventral and posterior views of a juvenile specimen, x 1, paratype USNM 153661e; 5, 6, posterior and side views of a strongly twisted young speci- men, X 1, paratype USNM 15366H; 7, 8, ventral and posterior views of another twisted, young specimen, x 1, paratype USNM 153661d; 9, 10, posterior and side views of a large, misshapen specimen, x 1, paratype USNM 153661a; 11-13, side, posterior, and ventral views of a young specimen having the form of a fishhook, x 1, paratype USNM 15366Ig; 14, 15, posterior and ventral views of a young, specimen with thin beak, X 1, paratype USNM 153661c; 16-18, pos- terior, ventral, and side views of a nearly full-grown individual, X 1, paratype USNM 153661h. [Skinner Ranch Formation (base), USNM 720c] 19, Posterior view of a siliceous cast of the interior, showing the strong median septum as a long slit, x 1, paratype USNM 153662. [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1473 PLATE 278.-Scacchinella 1474 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 279 Scacchinella Scacchinella titan, new species: 1-4, Ventral, side, dorsal, and posterior views of a large and perfect specimen, X 1, holotype USNM 147923a; 5-7, posterior, ventral, and side views of the brachial valve of the holotype, x 1, showing the large forked cardinal process and breviseptum (for an additional view of the holotype, see plate 282: figure 19). [Skinner Ranch Formation (Decie Ranch Member), USNM 707w.] 8, 9, Side and posteriorly tilted views of another brachial valve, x 2, showing the forked cardinal process and the elevated adductor attachments, paratype USNM 123919b. [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1475 PLATE 279.-Scacchinella 1476 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 280 Scacchinella Scacchinella titan, new species: 1, Posterior view of a long slender specimen, X 1, showing a twisted beak, paratype USNM 153664a; 2, 3, posterior and anteroventral views, X 1, showing the long median septum in the pedicle valve and the cardinal process of the brachial valve straddling it, paratype USNM 147923b; 4, 5, interior and posterior views of a brachial valve, X 1.5, showing the slitlike myophores of the cardinal process, paratype USNM 123920h (for additional views, see plate 281: figures 3-5); 6, full view of another brachial valve, X 1, showing thickening around adductor scars, paratype 123920e; 8, small specimen in posterior view, x 1, showing the broad interarea, paratype USNM 123920g. [Skinner Ranch Formation (Decie Ranch Member), USNM 707w.] 7, Anteroventral view of a specimen from which the exterior has been removed to show the vesicular plates of the pedicle valve and their relationship to the septum, x 1, paratype USNM 123919a. [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1477 PLATE 280.-Scacchinella 1478 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 281 Scacchinella Scacchinella titan, new species: 1, Partial side view of a small pedicle valve tilted to show the median septum, x 1, paratype USNM 123920i; 2, anteroventral view of a specimen from which the ventral side has been stripped, x 1, showing the long median septum of the pedicle valve and its relationship to the cardinal process, paratype USNM 123920a; 3-5, interior, side, and posterior views of the brachial valve, x 1, paratype USNM 123920h (for enlarged views of this specimen, see plate 280: figures 4, 5); 6-8, side, posterior and ventral views of a small specimen with others attached, x 1, showing mode of attachment and a brush of rhizoid spines, paratype USNM 123920d; 9, partial side view of a large specimen with window showing long median septum, X 1, paratype 153664b; 10-12, ventral, posterior, and side views of a pedicle valve, showing the median septum protruding beyond the shell margin, x 1, paratype USNM 147923c. [Skinner Ranch Formation (Decie Ranch Member), USNM 707w.] 13-15, Posterior, interior and side views of a young brachial valve, X 1, paratype USNM 153665a; 16-18, side, interior and partial posterior views of a more fully grown specimen than the preceding, X 1, paratype USNM 153665b. [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1479 PLATE 281.-Scacchinella 1480 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 282 Scacchinella Scacchinella titan, new species: 1-4, Ventral, posterior, dorsal, and side views of a small speci- men, x 1, paratype USNM 147991d; 5-7, side, ventral, and posterior views of a half-grown individual, x 1, paratype USNM 153666. [Skinner Ranch Formation (Decie Ranch Member), USNM 708q.] 8-10, Ventral, posterior, and side views of a young adult, x 1, paratype USNM 153667; 11-14, side, dorsal, ventral, and posterior views, x 1, of another small adult, paratype USNM 152685b; 15-17, dorsal, posterior, and ventral views of an immature specimen, X 1, paratype USNM 152685c; 18, dorsal view of a very small individual, X 1, paratype USNM 152685d. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707.] 19, Posterior view of the pedicle valve of the holotype USNM 147923a, X 1, without the brachial valve to show the distal, rounded end of the median septum (for additional views of the holotype, see plate 279). [Skinner Ranch Formation (Decie Ranch Member), USNM 707w.] NUMBER 19 1481 PLATE 282.-Scacchinella 1482 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 283 Scacchinella Scacchinella titan, new species: 1-4, Interior, posterior, side, and posteriorly tilted views of a large brachial valve, X 1, paratype USNM 153665c [Skinner Ranch Formation (base), USNM 705a.] 5-7, Ventral, side, and posterior views of an immature and much flattened specimen, x 1, paratype USNM 147991h; 8-11, dorsal, posterior, ventral, and side views of a young adult, X 1, paratype USNM 147991c; 12-14, posterior, side, and ventral views of an immature specimen, partially twisted, x 1, paratype USNM 147991e; 15, posterior of a middle-sized adult, X 1, para- type USNM 147991a. [Skinner Ranch Formation (Decie Ranch Member), USNM 708q.] 16-18, Ventral, posterior, and side views of a young adult, x 1, paratype USNM 153668b; 19-21, posterior, side, and ventral views of a large pedicle valve, x 1, paratype USNM 153668a. [Cibolo Formation (Breccia Zone), USNM 728k.] 22, Posterior view of a large adult, x 1, paratype USNM 152685a. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707.] NUMBER 19 1483 PLATE 28B.-Scacchinella 1484 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 284 Dyoros (Dyoros), Scacchinella, Sestropoma, and Acritosia Dyoros (Dyoros) endospinus, new species: 1-5, Dorsal, anterior, posterior, ventral, and side views of a complete specimen, x 1, paratype USNM 151917a; 6-10, dorsal, anterior, ventral, posterior, and side views of another complete specimen, X 1, holotype USNM 151917e; 11-13, three brachial valve interiors, X 1.5, showing spine development at the distal end of the median septum and the anderidia, paratypes USNM 151918a-c; 14, 15, pedicle valve interiors, X 1.5, showing spiny development anterior to the diductor scars, paratypes USNM 151918d, c [Road Canyon Forma- tion, USNM 707c] Scacchinella titan, new species: 16, Dorsal view of a small flatfish individual, X 2, paratype USNM 153673a; 17, ventral view of an immature specimen, x 2, paratype USNM 153673b; 18, posterior view of a larger, immature individual, X 2, paratype USNM 153673c; 19, immature specimen with part of pedicle valve broken away and showing the median septum, X 2, paratype USNM 153673d; 20, dorsal view of an immature specimen, showing presence of median septum by crack at beak, x 2, paratype USNM 153673e; 21, posterior of an immature specimen, showing part of the median septum and the cardinal process, x 2, paratype USNM 153673f; 22, anterior view of an immature form from which part of the pedicle valve has been stripped to show the median septum, x 2, paratype USNM 153673g; 23, 24, small attached specimen in anteroventral view, X 2, X 4, showing the median septum, paratype USNM 153673J; 25, dorsal view of an immature but complete specimen, x 2, paratype USNM 153673h; 26, same views of the pre- ceding immature paratypes (except figure 23), showing natural size; 27-29, posterior, ventral, and side views of small adult, x 1, showing dorsally directed ornament spines, paratype USNM 153673-1; 30, beak of preceding specimen, x 2, showing the dorsally directed spines. [Cibolo Formation (Breccia Zone of Udden), USNM 738r.] Sestropoma mexicanum, new species: 31-33, Side, dorsal, and posterior views of a large specimen, X 1, holotype USNM 153675 [Bed 25, Waagenoceras zone, USNM 815.] Acritosia teguliferoides (R. E. King): 34, 35, Dorsal and posterior views of a cluster of individuals attached to the brachial valve of Scacchinella titan, X 1, hypotype USNM 153674. [Cibolo Forma- tion (Breccia Zone of Udden), USNM 738r.] NUMBER 19 1485 PLATE 284.- Dyoros (Dyoros), Scacchinella, Sestropoma, and Acritosia 1486 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 285 Hercosia Hercosia delicata, new species: 1, Small cluster showing an individual with reflected margin, X 1, paratype USNM 154077a; 2, another small cluster, x 1, paratype USNM 154077b; 3, dorsal view, showing brachial valve in place, x 1, paratype USNM 154077c; 4-6, anterior, side, and dorsal views of a large pedicle valve, x 1, paratype USNM 152699d; 7, 8, anterior and dorsal views of an attached specimen, x 1, paratype USNM 154077e; 9-12, anterior, dorsal, side, and ventral views of a complete specimen, showing fine endospines on brachial valve, x I, paratype USNM 154077f; 13, 14, interior of the brachial valve, x 1, X 2, showing numerous long endo- spines, paratype USNM 154077g; 15-17, side, anterior, and dorsal views of a pedicle valve, X 1, paratype USNM 152699e; 18, 19, side and anterior views of an immature, squat specimen, X 1, paratype USNM 152699q; 20-22, side, dorsal, and anterior views of a complete specimen, X 1, paratype USNM 152699f; 23-25, anterior, dorsal, and ventral views of a complete speci- men, x 1, holotype USNM 152699u; 26, interior of the brachial valve of the holotype, X 2, showing cardinal process and endospines; 27, side view of an individual elongated by crowding, X 1, paratype USNM 152699p; 28, small cluster, the open specimen revealing the median septum, x 1, paratype USNM 154077J; 29, 30, specimens elongated by crowding, X 1, paratypes USNM 152699n, o; 31, dorsal view of an immature specimen, x 4, with both valves in place, paratype USNM 154078a; 32, dorsal view of a larger but immature specimen, X 4, paratype USNM 154078c; 33, dorsal view of an immature specimen without brachial valve, x 4, para- type USNM 154078b; 34, 35, posterior view, x 1, and dorsal view, x 2, showing the forked protective spines, paratype USNM 154106a; 36, dorsal view of a young specimen without pro- tective spines, x 1, paratype USNM 154077k; 37, side view of a broken specimen, showing the vesicular apical region and the bladelike septum, x 2, paratype USNM 154106b; 38, view similar to the preceding and showing the bladelike median septum and aulacoterma, X 2, paratype USNM 154106c [Cathedral Mountain Formation, USNM 726o.] NUMBER 19 1487 PLATE 285,-Hercosia 1488 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 286 Hercosia Hercosia uddeni (Bbse): 1, Cluster, x 1, showing crowding and elongation of individuals, hypotype USNM 154072a; 3, side view of a specimen attached to a fenestellid bryozoan, X 1, hypotype USNM 154105; 7, 8, side and anterior views of a narrowly tapering specimen, X 1, holo- type USNM 151715c [Cathedral Mountain Formation, USNM 702un.] 2, Cluster attached by rhizoid spines to a bryozoan, X 1, hypotype USNM 151716. [Cathedral Mountain Formation, USNM 703a.1] 4-6, Ventral, dorsal, and side views of a large cluster of adults, x 0.75, showing great crowding of individuals, hypotype USNM 151622a. [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1489 PLATE 286.-Hercosia V^~ œ^ KwkWWP 20 24 V ^ 26 * *m. 1504 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 294 Acritosia and Cyclacantharia Acritosia? vestibula, new species: 1, Dorsal view of a specimen preserving most of the protective spines on the anterior side, X 1, paratype USNM 151742a; 2-5, anterior, ventral, dorsal, and side views of a complete specimen, X 1, paratype USNM 151743a; 6-9, anterior, ventral, side, and dorsal views of another complete specimen, x 1, paratype USNM 151743f; 10, dorsal view, X 2, of an immature specimen, paratype USNM 151743i; 11-14, dorsal, side, ventral, and anterior views of a small specimen, x 1, paratype USNM 151743h; 15, 16, side and dorsal views of a specimen attached to a large pelecypod valve, X 1, paratype USNM 151742b. [Road Canyon Formation, USNM 702c] Cyclacantharia, species 4: 17, 18, Dorsal and side views of a small specimen attached to a branch of a bryozoan, x 1, figured specimen 154053. [Hess Formation (Taylor Ranch Member), USNM 702d.] Cyclacantharia transitoria, new species: 19, 20, Side and anterior views of a large cup, X 1, para- type USNM 152691c; 21-23, side, dorsal, and anterior views of a well formed cup, X 1, paratype USNM 152691a; 24-26, dorsal, anterior, and side views of the complete specimen, X 1, holotype USNM 152691b; 27, 28, interior of the brachial valve of the holotype, X 1, X 2, showing the cardinal process and the strongly developed protective spines. [Road Canyon Formation, USNM 724c] 29-31, Dorsal, anterior, and side views of a large, complete specimen with rhizoid spines, X 1, paratype USNM 152692a. [Road Canyon Formation, USNM 726j.] 32, 33, Side and dorsal views of another pedicle valve, with circle of protective spines, X 1, paratype USNM 152693b. [Road Canyon Formation, USNM 726d.] Cyclacantharia paucispinosa, new species: 34, 35, Anterior and side views of a large cup, X 1, paratype USNM 154065. [Road Canyon Formation (base), USNM 703a.] 36, Dorsal view of a broken specimen, showing the adductor callosity, X 1, paratype USNM 154066a; 37, another broken specimen, showing the adductor callosity and thick aulacoterma, X 1, paratype USNM 154066b. [Road Canyon Formation (base), USNM 702c] NUMBER 19 1505 PLATE 294.-Acritosia and Cyclacantharia 1506 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 295 Cyclacantharia Cyclacantharia gigantea, new species: 1, 2, Anterior and side views of a long slender specimen, X 1, paratype USNM 151647. [Skinner Ranch Formation (Decie Ranch Member), USNM 707a.] 3, 4, Side and anterior views of a large specimen, x 1, holotype USNM 151648; 5, 6, holotype broken at brachial valve, X 1. [Skinner Ranch Formation (Decie Ranch Member), USNM 714t.] Cyclacantharia robusta, new species: 7, Exterior of a brachial valve of Rhamnaria with spat of Cyclacantharia robusta, x 1, paratype USNM 154069o; 8, one of the preceding spat enlarged, X 2; 9-11, side, dorsal, and anterior views of a complete specimen, x 1, showing a circle of protective spines on the cup rim, paratype USNM 151645a; 12, 13, interior of the brachial valve of the preceding specimen, x 1, X 2, showing dendritic adductor scars, cardinal process and thick endospines. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1507 PLATE 295.-Cyclacantharia 1508 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 296 Cyclacantharia Cyclacantharia paucispinosa, new species: 1, 2, Interior of a poorly preserved brachial valve, X 1, X2, showing cardinal process and dendritic adductor scars, paratype USNM 151765c; 3, posterior of the preceding brachial valve, X 4, showing chilidium and myophore, 7, 8, 21, side and dorsal views of a young specimen, X 1, paratype USNM 151765c!; 14-16, side, dorsal, and anterior views of a young adult, X 1, paratype USNM 151766q; 17-20, dorsal, anterior, side and posterior views of a large adult, X 1, holotype USNM 151766t. [Road Canyon Formation (base), USNM 702c] 4-6, Side, anterior, and dorsal views of a young specimen, X 1, paratype USNM 154060b. [Road Canyon Formation, USNM 719x.] 9, 10, Anterior and side views of a pedicle valve attached to Edriosteges, x 1, paratype USNM 154062a; 11, 12, side and dorsal views of a short, squat cone, X 1, paratype USNM 154062b. [Road Canyon Formation, USNM 721z.] 13, Posterior view of a small cone with long marginal hood, X 1, paratype USNM 154061c [Road Canyon Formation (base), USNM 703a.] NUMBER 19 1509 PLATE 296.-Cyclacantharia 1510 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 297 Cyclacantharia Cyclacantharia paucispinosa, new species: 1, 2, Posterior and dorsal views of a stout pedicle valve, X 1, paratype USNM 151765a; 4, interior of a brachial valve, X 1, paratype USNM 151765b; 6, cluster of young individuals, X 1, paratype USNM 151765c [Road Canyon Forma- tion (base), USNM 702c] 3, Side view of a broken specimen, X 1, showing the vesicular shell in the apical and pos- terior regions, paratype USNM 154060a. [Road Canyon Formation, USNM 719x.] 5, Another imperfect pedicle valve, x I, showing the vesicular shell, paratype USNM 154061a; 7, interior of a pedicle valve, showing part of brachial valve in place, X 1, paratype USNM 154061b; 8, cluster of adult individuals, x 1, paratype USNM 154061c [Road Canyon Formation (base), USNM 703a.] Cyclacantharia robusta, new species: 9, Dorsal view of an immature specimen, X 2, paratype USNM 154059J; 10, 11, dorsal view of two spat, X 1, X 2, paratype USNM 154059m; 12, another immature specimen, x 2, paratype USNM 1540591; 13, anterior view of the interior of a pedicle valve, showing growth paths of sockets, X 1, paratype USNM 154059n; 14, partial side view of a broken pedicle valve, X 1, showing adductor callosity, paratype USNM 154059p; 15, 16, in- terior of the brachial valve, X 1, X 2, showing thick protective spines, paratype USNM 154059a; 17, side view of a broken pedicle valve, X 1, showing adductor callosity, paratype USNM 154059r; 18, interior of the posterior side of a pedicle valve, X 2, showing the growth path of the sockets and the groove in which the cardinal process is located, paratype USNM 154059s; 19, interior of another pedicle valve, X 2, showing the relationship of the grooves to the cardinal process and teeth and also showing inner extensions of the rhizoid spines of attachment, paratype USNM 154059t. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1511 PLATE 297.-Cyclacantharia 1512 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 298 Cyclacantharia Cyclacantharia kingorum agaricoidea, new subspecies: 1-3, Dorsal (apertural), ventral and an- terior views of a large specimen with reflected apertural margins, X 1, holotype USNM 151780a; 4, a small cluster of immature specimens, X 1, paratype USNM 151780c; 5-8, dorsal, ventral, an- terior, and side views of another specimen with reflected apertural sides, X 1, paratype USNM 151780b. [Word Formation (lens between Willis and Appel Ranch members), USNM 706b.] Cyclacantharia kingorum Cooper and Grant: 9, Young, elongated pedicle valve, X 1, hypo- type USNM 154064a; 10, another young elongated pedicle valve, side view, X 1, hypotype USNM 154064c; 11, 12, side and dorsal views of an elongated cup, X 1, showing rhizoid spines and brachial valve in feeding position (?), X 1, paratype USNM 123918; 13-15, dorsal, side, and anterior views, X 1, showing rhizoid spines and crowded apertural spines, holotype USNM 153831; 16, posterior view of a specimen with brachial valve in feeding position (?), X 1, hypotype USNM 151785d; 17, dorsal view of a specimen with brachial valve in feeding (?) position, X 1, hypotype USNM 153832; 18, dorsal view of a specimen with brachial valve in feeding (?) posi- tion but with small protective spines, X 2, hypotype USNM 151786w; 19, side view of a cluster of crowded specimens, X 1, hypotype USNM 151785c (for apertural view, see plate 299: figure 20). [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1513 PLATE 298.-Cyclacantharia 1514 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 299 Cyclacantharia Cyclacantharia kingorum Cooper and Grant: 1, 2, Interior and exterior of a brachial valve, X 1, hypotype USNM 124140d; 3, interior of the preceding specimen, x 2, showing cardinal process and endospines: 4, 5, interior and exterior of another brachial valve, X 1, paratype USNM 124140a; 6, interior of the preceding specimen, x 2; 7, 8, exterior and interior of a brachial valve, X 1, paratype USNM 124140b; 9, interior of the preceding specimen, X 2, show- ing stout endospines; 10, exterior of a brachial valve, X 1, hypotype USNM 124140c; 11, interior and posterior views of the preceding specimen, x 2, showing cardinal process and endospines; 12, posterior view of the preceding brachial valve, X 3, showing chilidium over the myophore of the cardinal process; 15, 16, side and dorsal views of a cluster of immature specimens, X 3, showing spiny brachial valves and incipient protective spines, paratype USNM 123917b; 17, dorsal view of a specimen, showing brachial valve in place (feeding position?), and the ring of striated protective spines surrounding the aperture, X 2, hypotype USNM 151786v; 18, dorsal view of the aperture of another specimen, X 2, showing branched and striated protective spines and a healed injury in the southeast quadrant, paratype USNM 123917a; 20, dorsal view of another specimen with brachial valve in feeding (?) position and showing the crowded protective spines on the anterior side, X 1, hypotype USNM 151785c (for side view, see plate 298: figure 19). [Word Formation (Willis Ranch Member), USNM 706c] 13, 14, Anterior and dorsal views of a large pedicle valve, showing interrupted growth stages and the circle of spines around the aperture, X 1, hypotype USNM 154535b; 19, anterior view of two specimens attached on a length of crinoid stem, x 1, hypotype USNM 154535a. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1515 PLATE 299.-Cyclacantharia 1516 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 300 Cyclacantharia Cyclacantharia kingorum Cooper and Grant: 1, Dorsal view of six immature, complete specimens having no protective spines, x 1, hypotypes USNM 154063a-f; 2, 3, ventral and dorsal views of a cluster of immature valves attached to a fragment of pelecypod shell, X 1, hypotype USNM 154063g; 4, dorsal view of an immature specimen, x 1, hypotype USNM 154063p; 5, imperfect pedicle valve, x 1, showing vesicular area, hypotype USNM 154063h; 7, dorsal view of an im- mature specimen showing development of the protective spine ring, x 1, hypotype USNM 154063i; 8, dorsal view of two attached individuals showing incipient development of protective spines, X 1, hypotype USNM 154063J; 9, 10, dorsal view of a group of immature specimens attached to Collemataria, X 1, X 2, hypotype USNM 154063k; 11, dorsal view of another group of immature specimens attached to Collemataria, x 1, hypotype USNM 154063-1; 12, 13, dorsal view of an immature specimen starting life on the concave surface of a productid brachial valve exterior, X 2, X 1, hypotype USNM 154063m; 14, dorsal view of a fairly large immature specimen not yet having developed protective spines, x 2, hypotype USNM 154063e (middle specimen in figure 1); 15, dorsal view, X 1, of a specimen with several spat on the brachial valve, X 1, hypotype USNM 154063n; 16, dorsal view of a specimen in which the protective spines com- pletely cover the aperture, x 1, hypotype USNM 154063o; 18, side view of a cluster of adults attached by their spines, X 1, hypotype USNM 151785b; 19, dorsal view of a cluster of immature specimens with incipient protective spines, X 1, hypotype USNM 154063q; 20, exterior of a brachial valve of Rhamnaria occupied by immature specimens seen in dorsal view, x 1, hypotype USNM 154063r; 21, dorsal view of an immature individual, x 2, same as lower right in figure 1; 22, 23, dorsal and side views of a cluster of adult specimens showing protective and rhizoid spines, X 1, hypotype USNM 151785a; 24, cross section of a pedicle valve, showing hinge region, X 1, hypotype USNM 124168a; 25, matted cluster of immature specimens, x I, hypotype USNM 154063s. [Word Formation (Willis Ranch Member), USNM 706c] 6, Two specimens in side view, X 1, showing tangle of rhizoid spines binding them together, hypotype USNM 151782a; 17, anterior view of a large adult, showing its mass of rhizoid spines, X 1, hypotype USNM 151782b. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1517 PLATE 300.-Cyclacantharia <&<9 1518 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 301 Hercosia and Cyclacantharia Hercosia delicata, new species: 1, 2, Dorsal and ventral views of a small cluster, X 1, paratype USNM 154077L [Cathedral Mountain Formation, USNM 726o.] Cyclacantharia kingorum Cooper and Grant: 3, Dorsal view of a cluster of young specimens of various sizes attached to a large adult, X 1, hypotype of USNM 154064d; 4, 5, spat attached to the brachial valve of Rhamnaria, x 1, X 2, hypotype USNM 154064e; 6, 23, spat attached to a young Collemataria, X 1, X 2, hypotype USNM 154064f; 7, cluster of spat occupying the exterior of a Collemataria, x 1, hypotype USNM 154064g; 8, young individual attached to the brachial valve of Paucispinifera, X 1, hypotype USNM 154064h; 9, 10, dorsal and posterior views of a small adult with small protective spines, x 1, paratype USNM 124166; 11, large specimen of Collemataria partially covered by spat of Cyclacantharia, X 1, paratype USNM 124165a; 12, interior of a pedicle valve, X 1, showing hinge region and its growth track, hypotype USNM 154064i; 13, interior of another broken pedicle valve, X 1, showing brachial valve in position and the track of the hinge area, hypotype USNM 154064J; 14, interior of another pedicle valve, side view, x 1, showing aulacoterma, and vesicular region at the apex, hypotype USNM 154064k; 15, pedicle valve interior, anterior side, X 1, showing adductor callosity hypotype USNM 154064-1; 16, 17, halves of the same pedicle valve, showing vesicular tissue, adductor callosity and aulacoterma, x 1, hypotypes USNM 154064m, n; 18, interior of an elongated specimen, X 1, showing posterior part of brachial valve in place and the growth path of the hinge, hypotype USNM 154064o; 19, interior of a pedicle valve, showing the adductor callosity, X 1, hypotype USNM 154064p; 20, fragment of the posterior of a pedicle valve, x 2, showing aulacoterma and growth tracks of rhizoid spines of the exterior, hypotype USNM 154064q; 21, 22, two parts of one pedicle valve of another specimen, x 2, showing bases of protective spines, brachial valve in place, adductor callosity and growth path of the hinge, paratype USNM 154064r. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1519 PLATE 301.-Hercosia and Cyclacantharia MM 1520 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 302 Cyclacantharia Cyclacantharia robusta, new species: 1, 2, Side and dorsal views of a cluster of small individuals, X 1, paratype USNM 154059b; 3, 4, anterior and side views of another small specimen, X 1, paratype USNM 154059c; 5, 6, side and anterior views of a pedicle valve attached to a small cluster, X 1, paratype USNM 154059d; 7, side view of the preceding cluster, x 1; 8, anterior view of a small, elongate pedicle valve, X 1, paratype USNM 154059-1; 9-11, side, anterior, and dorsal views of a specimen with long protective spines over the aperture, X 1, paratype USNM 151645b; 12-14, anterior, side, and posterior views of a small pedicle valve, X 1, paratype USNM 154059e; 15, 16, side and posterior views of a young pedicle valve, X 1, paratype USNM 154059f; 17, 18, interior of a brachial valve, X 1, X 2, showing stout protective spines, paratype USNM 154059g; 19, dorsal view, showing brachial valve in place, X 1, paratype USNM 151646g; 20-22, side, dorsal (apertural), and anterior views of a full-grown adult, x 1, holotype USNM 151646b; 23, 24, interior of the brachial valve of the holotype, X 1, X 2, showing numerous stout protective spine bases; 25-27, side, posterior, and dorsal views of another large adult, X 1, paratype USNM 151646a; 28, 29, anterior and dorsal views of a long slender specimen, x 1, paratype USNM 151646e; 30, interior of a pedicle valve, X 1, showing aulacoterma and adductor callosity, paratype USNM 154059u; 31, dorsal view of an immature specimen, x 1, paratype USNM 154059k; 32, dorsal (apertural) view of a pedicle valve, showing adductor callosity and hingement, X 1, paratype USNM 151646J. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1521 PLATE S02.-Cyclacantharia 1522 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 303 Taphrosestria Taphrosestria peculiaris, new species: 1-5, Anterior, ventral, dorsal, side, and posterior views, X 1, of the holotype USNM 154082a; 6-10, dorsal (apertural), ventral, anterior, side and posterior views of another pedicle valve, X 1, paratype USNM 154082b. [Road Canyon Forma- tion, USNM 721y.] Taphrosestria species: 11, Dorsal view of a squat, thick-shelled species, X I, figured specimen USNM 154083a. [Cathedral Mountain Formation, USNM 702-low.] Taphrosestria expansa, new species: 12-15, Anterior, side, dorsal, and ventral views, X 1, of the holotype USNM 152688h; 16, 17, interior and exterior of the brachial valve from the holotype, X 2, showing no endospines but strong external spines; 18, 19, anterior and dorsal views of a pedicle valve, showing the muscle region, x 1, paratype USNM 154084; 20-23, dorsal, side, ventral, and posterior views of a pedicle valve, X 1, paratype USNM 152688f; 24-26, side, ventral, and dorsal views of a complete specimen, x 1, paratype USNM 152688b; 27, interior of the brachial valve, X 2, of the preceding paratype with only vestigial endospines; 28-30, dorsal, anterior, and side views of a narrow pedicle valve, x 1, paratype USNM 152688d; 31-33, dorsal, anterior, and side view of another pedicle valve with stout protective spines, X I, paratype USNM 152688c [Road Canyon Formation, USNM 724b.] NUMBER 19 1523 PLATE 303.-Taphrosestria 1524 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 304 Taphrosestria Taphrosestria peculiaris, new species: 1-5, Anterior, ventral, posterior, side, and dorsal views, X 1, of a small specimen, paratype USNM 151760h; 6, dorsal view of the preceding, x 2, showing the fused protective spines; 7-11, dorsal, posterior, ventral, side and anterior views of another specimen, x I, paratype USNM 151760f; 12-16, dorsal, posterior, ventral, anterior, and side views of an average specimen, x 1, paratype USNM 151760d; 17, dorsal view of the preceding specimen, x 2, showing spines fusing together; 18-22, side, anterior, ventral, posterior, and dorsal views of a small individual, x 1, paratype USNM 151760g; 23-27, dorsal, side, posterior, an- terior, and ventral views of a pedicle valve, showing tiered marginal flanges, X 1, paratype USNM 151760a; 28, dorsal view of the preceding specimen, X 2, showing the tiered flanges and fusing protective spines; 29-33, dorsal, posterior, side, anterior, and ventral views of a small individual, x 1, paratype USNM 151760i; 34, dorsal view of the preceding paratype, X 2, showing the fused, protective spines; 35, 36, side and dorsal views of specimen with tiered marginal flanges and rhizoid spines, X 1, paratype USNM 154109; 37, 38, interior of the pedicle valve, X 1, X 2, showing thickened muscle area and openings of rhizoid spines, paratype USNM 151760m; 39, 40, dorsal and side views of two attached specimens, X 1, paratype USNM 154085; 41, interior of a pedicle valve, X 1, showing thick muscle field, paratype USNM 151760n; 42, pedicle valve attached to Coscinophora, x 1, paratype USNM 151759a; 43, interior of a pedicle valve, x 2, showing hinge region and "valva falsa," paratype USNM 151760o; 44, interior of a broken specimen, showing the vesicular regions and the brachial valve in place, X 1, paratype USNM 151760p; 45, broken pedicle valve, X 2, showing brachial valve in place, para- type USNM 15l760q. [Road Canyon Formation, 710u.] NUMBER 19 1525 PLATE 304.-Taphrosestria 1526 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 305 Taphrosestria and Collumatus Taphrosestria peculiaris, new species: 1-3, Dorsal, side, and anterior views of a specimen with tiered marginal flanges, x 1, paratype USNM 151759c; 4, 5, side and dorsal views of two attached individuals, X 1, paratype USNM 151759e; 6, 7, dorsal and side view of a specimen with tiered marginal flanges, X 1, paratype USNM 151759d; 10, 11, interior and exterior views of a brachial valve, X 2, showing coarse spine bases on the exterior and thickened adductor patches on the interior, paratype USNM 154087; 19, 20, interior of a broken specimen, showing the brachial valve in place, x 1, X 2, paratype USNM 151759L [Road Canyon Formation, USNM 710u.] 8, 9, Dorsal and anterior views of a complete specimen, showing coarse pustules on brachial valve, X 1, paratype USNM 154086. [Road Canyon Formation, USNM 723x.] 12, 13, Dorsal view of a complete specimen, x 1, X 2, showing coarse spines on the brachial valve, paratype USNM 151757a; 14, 15, dorsal and side views of complete specimen, x 1, para- type USNM 151757b; 16, interior of a pedicle valve, showing hinge region, x 1, paratype USNM 151757c; 17, 18, anterior and dorsal views of a pedicle valve, showing filled in protective spine area and the muscle callosity, X 1, paratype USNM 151757d. [Road Canyon Formation, USNM 707c] Collumatus solitarius Cooper and Grant: 21-23, Anterior, side, and ventral views of a pedicle valve, x 1, hypotype USNM 154088a; 26-29, ventral, side, dorsal, and dorsal tilted views of a pedicle valve, X 1, showing adductor callosity, hypotype USNM 154088b (for enlargement see plate 306: figure 31); 30-33, dorsal, ventral, side, and anterior views of another pedicle valve, X 1, hypotype USNM 154088c; 34-36, dorsal, side, and ventral views of a young specimen attached to the valve of a Neospirifer, x 1, hypotype USNM 154088d; 43, 44, side and anterior views of a well formed pedicle valve, x 1, hypotype USNM 154088e; 49-52, side, ventral, dorsal, and side views of two individuals attached to a fragment of Meekella, X 1, hypotype USNM 153043o; 53, broken specimen, X 2, showing part of brachial valve in place and lateral layers of attachment, hypotype USNM 154088f. [Road Canyon Formation, USNM 732j.] 24, 25, Dorsal and ventral views of a small individual, showing attachment rings and brachial valve in place, x 1, hypotype USNM 154089a; 37-40, anterior, dorsal, side, and ventral views of a large specimen, x 1, hypotype USNM 154089b; 41, 42, dorsal and ventral views of a pedicle valve, X 1, showing aulacoterma and rings of attachment, x 1, hypotype USNM 154089c; 45-48, dorsal, anterior, side, and partial ventral views, x 1, showing sheets of shell for attachment, hypotype USNM 154089d. [Road Canyon Formation, USNM 700v.] NUMBER 19 1527 PLATE 305.-Taphrosestria and Collumatus tiffin %^^/%'':-r 13 1528 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 306 Collumatus and Sestropoma Collumatus solitarius Cooper and Grant: 1, 2, Ventral and side views of a pedicle valve, showing the concentric layers of attachment, X 1, hypotype USNM 153043d; 3-6, anterior tilted, anterior, ventral, and side views of a young specimen, showing concentric layers, X 1, hypotype USNM 154088g; 7-9, anterior, ventral, and dorsal views of a small pedicle valve, X 1, hypotype USNM 154088h; 10-12, dorsal, side, and anterior views of a complete specimen, x 1, hypotype USNM 154088i; 13-15, ventral, anterior and side views of an immature specimen, x 1, hypotype USNM 154088J; 16, 17, ventral and anterior views of a pedicle valve, X 2, showing concentric layers of attachment shell, hypotype USNM 153043b; 18, 19, anterior and dorsal views of a pedicle valve, X 1, hypotype USNM 153043a; 20, 21, interior and exterior, X 3, of the brachial valve belonging to the preceding hypotype; 22-26, side, dorsal, ventral, anterior, and opposite side views, X 1, of a specimen preserving the coscinidium, hypotype USNM 154090; 27, 28, an- terior and dorsal views of the preceding hypotype, X 2, showing granular texture of shell body; 29, 30, exterior and interior of another brachial valve, X 3, showing cardinal process and dendritic adductor scars, hypotype USNM 153043p; 31, dorsal view, X 2, showing adductor callosity, hypotype USNM 154088b (for additional views of this specimen, see plate 305: figures 26-29); 32-34, anterior, dorsal, and side views of a nearly complete specimen, X 1, paratype USNM 153043c; 35, dorsal view of the preceding paratype showing bases of coscinidium, X 2. [Road Canyon Formation, USNM 732j.] Sestropoma cribriferum Cooper and Grant: 36-38, Anterior, side, and dorsal views of a complete specimen, x 1, hypotype USNM 154080g; 39-41, side, anterior, and dorsal views of specimen with wide marginal flange, X 1, hypotype USNM 154080a; 42-44, anterior, side, and dorsal views of a small specimen, X 1, hypotype USNM 154080d; 45-47, dorsal, side, and anterior views of a complete specimen, X 1, hypotype USNM 154080c; 48, dorsal view of the preceding specimen, X 1.5, showing well formed coscinidium; 49, 50, exterior and interior of the brachial valve, X 2, showing scattered coarse endospines and smooth exterior, hypotype USNM 154080k; 51, interior of a broken specimen, showing the adductor callosity, X 1, hypotype USNM 154080-1. [Bell Canyon Formation (Rader Member), USNM 725f.] NUMBER 19 1529 PLATE 306.-Collumatus and Sestropoma 1530 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 307 Sestropoma Sestropoma cribriferum Cooper and Grant: 1-3, Dorsal, anterior and side views of a complete specimen with broken coscinidium, x 1, showing brachial valve in place, X 1, hypotype USNM 154079a; 4-6, anterior, side, and dorsal views of a complete specimen with coscinidium, x 1, hypotype USNM 154079e; 7, anterior view, X 1.5, of the preceding specimen, showing coscinidium and rhizoid spines; 8, interior of a pedicle valve, X 2, showing hinge area, adductor callosity and basal part of coscinidium, hypotype USNM 154080b. [Bell Canyon Formation (Rader Mem- ber), USNM 725f.] 9, Dorsal view of a young specimen with complete coscinidium, X 1, paratype USNM 151656f; 10, 11, side and dorsal (apertural) views of an adult without coscinidium, x 1, showing the carinate adductor callosity, paratype USNM 151656h; 12, 13, dorsal and anterior views of a young individual, X I, paratype USNM 1516561; 17-19, dorsal, side, and anterior views of a large paratype with thick spines, X 1, USNM 151656a; 20-23, anterior, dorsal, and side views, X 1, and dorsal view, X 1.5, of the holotype USNM 151656b; 24-26, dorsal, side, and anterior views of a complete specimen with thick spines, X 1, paratype USNM 151656c; 28, dorsal view of a small specimen, x 1, paratype USNM 151656J; 29, fragment of a pedicle valve interior, X 1, showing adductor callosity, hypotype USNM 151656-1; 30, side view of a specimen elongated by crowding, X 1, hypotype USNM 151656m; 31, side view of a small specimen, x 1, paratype USNM 151656k; 32, 33, exterior and interior views of the brachial valve of the preceding speci- men, X 3, showing cardinal process and scattered stout endospine bases. [Bell Canyon Formation (Hegler Member), USNM 731.] 14-16, Dorsal, anterior, and side views of a complete specimen, x 1, hypotype USNM 151665. [Bell Canyon Formation (probably Hegler Member), AMNH 397.] 27, Small cluster, x 1, showing the stout rhizoid spines, hypotype USNM 154081a. [Bell Canyon Formation (Hegler Member), USNM 732a.] NUMBER 19 1531 PLATE 307.-Sestropoma * WW, 1532 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 308 Acristosia, Cyclacantharia, and Sestropoma Acritosia? vestibula, new species: 1, Dorsal view of an attached pedicle valve, X 1, paratype USNM 151743J; 2-5, ventral, anterior, side, and dorsal views, X 1, holotype USNM 151743b. [Road Canyon Formation (base) USNM 702c] Cyclacantharia kingorum Cooper and Grant: 6, Side view of a young specimen with rhizoid spines, X 1, hypotype USNM 154063t. [Word Formation (Willis Ranch Member), USNM 706c] 22, Longitudinal section, showing vesicular shell in the apical part, X 1, hypotype USNM 151782c; 23, polished longitudinal section of another specimen, showing the vesicular shell in the apical region, X 1, hypotype USNM 154054. [Word Formation (Willis Ranch Member), USNM 723w.] Cyclacantharia species 5: 7-9, Side, posterior, and dorsal (apertural) views of a well formed cup showing a circle of protective spines, X 1, figured specimen USNM 151641. [Bell Canyon Formation, AMNH 404.] Sestropoma cribriferum Cooper and Grant: 10, Interior of a broken specimen, showing the thick, carinate adductor callosity, x 1, hypotype USNM 154056a; 11, partial side view of another broken specimen, showing the adductor callosity and basal parts of the protective net or coscinidium, x 1, hypotype USNM 154056b; 20, small cluster of specimens attached to a pro- ductid, X 1, hypotype USNM 154056c [Bell Canyon Formation (Hegler Member), USNM 731.] 12, Interior, x 1, showing growth track of sockets and the valva falsa with base of coscinidium, hypotype USNM 151671a; 13, side view of a small specimen, showing brachial valve in place (in cross section), X 1, hypotype USNM 151671b. [Bell Canyon Formation (probably Hegler Member), AMNH 404.] 14, 15, Two views of a broken pedicle valve, showing the aulacoterma and adductor callosity, X 1, hypotype USNM 151670d; 16, interior of another pedicle valve, x 1, showing the adductor callosity, hypotype USNM 151670f. [Bell Canyon Formation (Rader Member), AMNH 410.] Interior of a pedicle valve in anterior view, showing track of socket growth and the base of the coscinidium, x 1, hypotype USNM 154057. [Bell Canyon Formation (Pinery Member), USNM 733.] Dorsal view of a pedicle valve, showing the adductor callosity, X 1, hypotype USNM 151668. [Bell Canyon Formation (Rader Member), AMNH 403.] Two specimens attached by rhizoid spines, x 1, hypotype USNM 151676. [Bell Canyon Formation (Lamar Member), AMNH 39.] 21, Dorsal (apertural) view of a specimen in which the coscinidium has not yet been com- pleted, x 2, figured specimen 152694. [Bell Canyon Formation (Hegler Member), USNM 731.] Acritosia magnifica, new species: 24, 25, Side and anterior views of rotund pedicle valve, showing squat form of early stage, X 1, paratype USNM 154055a; 26, 27, dorsal and anterior views of a squat individual, X 1, holotype USNM 154055b, showing the hunched shoulders of the brachial valve. [Road Canyon Formation, USNM 724j.] NUMBER 19 1533 PLATE 308.-Acritosia, Cyclacantharia, and Sestropoma ^ % -^#^# B^P 1534 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 309 Acritosia, Hercosia, Teguliferina, Collumatus, and Cyclacantharia Acitosia silicica, new species: 1, 2, Dorsal view, x 1, X 2, of the pedicle valve, holotype USNM 152687c; 3-5, interior, X 1, and exterior and interior, X 3, of the brachial valve of the holotype showing external granules, the cardinal process and endospines. [Hueco Formation, USNM 725b.] Hercosia uddeni (Bose): 6, Anterior view of a small cluster attached to the pedicle valve of Colle- mataria, X 1, hypotype USNM 154112. [Cathedral Mountain Formation, USNM 702un.] 15, Dorsal view of a specimen with strong, long protective spines and a flaring marginal flange, X 1, hypotype USNM 154113. [Cathedral Mountain Formation, USNM 735b.] Teguliferina conida (Stehli): 7-9, Ventral, anterior, and dorsal views of a complete specimen with tiered marginal flanges and dorsal valve, x 1, hypotype USNM 154098b; 10, 11, side and interior views of the brachial valve of the preceding specimen showing a strong breviseptum' but only vestigial endospines, X 1; 12-14, exterior view, X 1, and interior and side views of another brachial valve with stubby endospines but strong median ridge, X 2, hypotype USNM 154111. [Bone Spring Formation, USNM 728f.] Collumatus solitarius Cooper and Grant: 16, Side of a small pedicle valve cemented to a branch of a bryozoan, x 1, hypotype USNM 154114a; 17-20, posterior, both sides, and ventral views of the preceding specimen showing mode of attachment to the bryozoan, X 2; 21, anterior view of a small pedicle valve with coscinidium well preserved, X 1, hypotype USNM 154114b; 22-26, ven- tral, anterior, side posterior, and dorsal views of the preceding specimen, x 2, showing coscin- idium, 27-29, sides of three specimens, X 1, showing lamellae used for attachment, hypotype USNM 154526a-c [Road Canyon Formation, USNM 732j.] Cyclacantharia kingorum Cooper and Grant: 30, Anterior view of a large pedicle valve with small, crowded specimens attached to its side and elongated by the close crowding, x 1, USNM 154064b. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1535 PLATE 309.-Acritosia, Hercosia, Teguliferina, Collumatus and Cyclacantharia 1536 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 310 Fimbrinia, Simplicarina, Oncosarina, and Costispinifera Fimbrinia ovata, new species: 1-4, Ventral, posterior, anterior, and side views of a pedicle valve, X 1, paratype USNM 153873; 5, 6, side and ventral views, X 2, of the preceding specimen. [Bone Spring Formation, USNM 728h.] 7-10, Posterior, ventral, anterior, and side views, X 1, of another paratype USNM 152701-1; 11, 12, side and ventral views of the preceding specimen, X 2; 13-15, posterior, anterior, and ventral views of a paratype, X 1, USNM 152701m; 16, 17, ventral and side views of the preceding paratype, x 2; 18-20, anterior, ventral, and side views of the holotype, x 1, USNM 152701a; 21, 22, side and ventral views of the holotype, x 2; 23, exterior, of a brachial valve, X 2, paratype USNM 15270H; 24, 25, exterior, X 2, and interior X 4, of another brachial valve, paratype USNM 152701 j; 26, interior of a brachial valve, X 4, showing platforms, paratype USNM 152701k. [Bone Spring Formation, USNM 728f.] 27, 28, Dorsal view, x 1, X 2, of a complete specimen, paratype USNM 153874c; 29, exterior of a small brachial valve, x 2, paratype USNM 153874b; 30, interior, X 4, of the preceding specimen; 31, exterior of an imperfect valve, X 2, paratype USNM 153874a. [Skinner Ranch Formation (base), USNM 705a.] Fimbrinia species 2: 32, Dorsal view of a poorly preserved complete specimen, X 2, figured specimen USNM 153876. [Neal Ranch Formation (bed 4 of P. B. King), USNM 727c] Fimbrinia species 3: 33, 34, Ventral views, X 1, X 4, of a small pedicle valve, figured specimen USNM 153877. [Cibolo Formation (Breccia Zone of Udden), USNM 728-1.] Simplicarina incompta, new species: 35-39, Posterior, dorsal, side, anterior, and ventral views of the holotype, x 1, USNM 153927a; 40, 41, side and dorsal views, X 2, of the holotype. [Road Canyon Formation, USNM 726d.] Oncosarina whitei (R. E. King): 42-44, Anterior, ventral, and side views of a pedicle valve, X 1, hypotype USNM 149843. [Hess Formation (Taylor Ranch Member), USNM 716n.] 45-47, Ventral, side, and anterior views of another pedicle valve, X 1, hypotype USNM 149845d; 48-50, ventral, side, and anterior views of a small pedicle valve, X 1, hypotype USNM 149845c [Hess Formation Taylor Ranch Member), USNM 716o.] 51-55, Dorsal, side, posterior, anterior, and ventral views of a complete specimen, x 1, hypo- type USNM 149840. [Hess Formation (Taylor Ranch Member), USNM 702m.] 56, Interior of the brachial valve, X 2, showing the elevated adductor platforms, hypotype USNM 153195. [Hess Formation (Taylor Ranch Member), USNM 722p.] 57-61, Anterior, posterior, side, ventral, and dorsal views of another complete specimen, x 1, hypotype USNM 149838. [Hess Formation (Taylor Ranch Member), USNM 702f.] Costispinifera rugatula (Girty): 62-65, Ventral, posterior, side, and dorsal views of a complete specimen, X 1, hypotype USNM 153878a; 66-70, side, posterior, anterior, dorsal, and ventral views of another complete specimen, x 1, hypotype USNM 153878b. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1537 PLATE 310.-Fimbrinia, Simplicarina, Oncosarina, and Costispinifera 1538 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 311 Fimbrinia and Rhytisia Fimbrinia species 1: 1, 2, Dorsal view, X 1, X 2, of a brachial valve, figured specimen, USNM 153999b; 3, 4, ventral views of a pedicle valve, X 2, X 1, figured specimen USNM 153999a. [Lenox Hills Formation (base), USNM 707j.] Fimbrinia plummeri (R. H. King): 5-9, Ventral, side, anterior, posterior, and dorsal views of a pedicle valve, x 1, hypotype YPM 11499a; 10, 11, ventral and side views, x 2, of the preceding specimen; 12, 13, ventral and side views of another pedicle valve, X 1, hypotype YPM 11499b; 14, side view, X 2, of the preceding specimen. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), R. E. King, locality 94.] Rhytisia rugosa, new species: 15-18, Ventral, posterior, side, and anterior views of a pedicle valve, X 1, paratype USNM 152704a; 19, 20, ventral and side views, X 2, of the preceding specimen; 21, ventral view of a small pedicle valve, X 1, paratype USNM 152704d; 22-24, ventral, side, and posterior views, X 2, of the preceding specimen, showing the wrinkled umbonal region; 25, 26, ventral, x 1, and dorsal, X 2, views of a complete specimen, paratype USNM 152704b; 27, 28, posterior and interior views, X 4, of a brachial valve, showing cardinal process and breviseptum, paratype USNM 1527041; 29, 30, posterior and interior views, X 4, of another brachial valve, show- ing strong ear baffles, paratype USNM 152704j; 31, 32, exterior, X 1, and interior, X 4, of a brachial valve, paratype USNM 152704k. [Road Canyon Formation, USNM 724c] 33-35, Ventral, posterior, and anterior views of a pedicle valve, X 1, paratype USNM 152703e; 36, ventral view, X 3, of the preceding specimen; 37, 38, dorsal views of a complete specimen, X 1, X 2, holotype USNM 152703c; 39, ventral view, X 3, of the holotype; 40, ventral view of a strongly wrinkled pedicle valve, X 2, paratype USNM 152703f; 41, ventral view of another wrinkled specimen, x 2, paratype USNM 152703g; 42, 43, exterior, X 3, and interior, X 4, of a wrinkled brachial valve, paratype USNM 152703h; 44, exterior of a brachial valve, X 2, showing wrinkles, paratype USNM 152703i; 45, 46, posterior and interior of the preceding specimen, X 3, showing cardinal process; 47, exterior of another brachial valve, X 2, showing wrinkles, paratype USNM 152703-1; 48, ventral view of a pedicle valve, x 2, paratype USNM 152703b; 49, exterior of a brachial valve, X 2, paratype USNM 152703k; 50, 51, posterior and interior views, X 3, of the preceding specimen. [Road Canyon Formation, USNM 721z.] 52, 53, Ventral and posterior views of a pedicle valve, x 2, paratype USNM 152979c; 54-56, ventral and posterior views, X 2, and ventral view, X 1, of another pedicle valve, paratype USNM 152979a. [Road Canyon Formation, USNM 721j.] 57, Ventral view of a pedicle valve preserving the initial attachment ring, X 2, paratype USNM 154000a; 58, 59, ventral view of another pedicle valve, X 1, X 3, showing its stout halteroid spines, paratype USNM 154000b. [Road Canyon Formation, USNM 726d.] NUMBER 19 1539 PLATE 311.-Fimbrinia and Rhytisia 1540 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 312 Kozlowskia, Costispinifera, and Simplicarina Kozlowskia alata, new species: 1-4, Ventral, dorsal, posterior, and anterior views of a complete specimen, X 1, holotype USNM 149800d; 5-8, anterior, ventral, posterior, and dorsal views of another complete specimen, x 1, paratype USNM 149800b; 9-11, anterior, side, and interior views of a brachial valve, X 1, showing margin and long trail, paratype USNM 149799b; 12, 13, posterodorsal and interior views of the preceding brachial valve, X 2, showing fluted ear baffles and cardinal process; 14, posterior of the preceding, X 3, showing the cardinal process; 15-17, interior, anterior, and side views of an alate brachial valve, X 1, showing the margin and trail, paratype USNM 149799a; 18, 19, interior and posterodorsal views of the preceding, X 2, showing elevated muscle scars, brachial ridges, and cardinal process; 20, posterodorsal view of the preced- ing, x 3, showing the cardinal process (for an additional view of this specimen see plate 453: figure 34.) [Skinner Ranch Formation (base), USNM 705a.] Costispinifera rugatula (Girty): 21-24, anterior, side, posterior, and ventral views of a large pedicle valve, X 1, hypotype USNM 153905. [Word Formation (China Tank Member), USNM 706c] Simplicarina incompta, new species: 25-28, Exterior, X 1, and interior, posterior, and exterior, X 2, of a brachial valve, paratype USNM 151585c; 29-32, exterior, X 1, and interior, exterior, and posterior, X 2, of another brachial valve, showing the small, narrow cardinal process and broad brachial ridges, paratype USNM 151585b; 33-36, side, posterior, anterior, and dorsal views of a complete specimen, x 1, paratype USNM 151585a; 37-41, posterior, anterior, ventral, side, and dorsal views of the preceding specimen, x 2. [Road Canyon Formation, USNM 721 j.] 42-45, Dorsal, anterior, posterior, and side views of a complete specimen preserving parts of its spines, X 1, paratype USNM 151583; 46-50, posterior, anterior, ventral, side, and dorsal views of the same paratype, X 2. [Road Canyon Formation, USNM 720d.] NUMBER 19 1541 PLATE 312.-Kozlowskia, Costispinifera, and Simplicarina 1542 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 313 Kozlowskia Kozlowskia anterosulcata, new species: 1-4, Anterior, ventral, posterior, and side views of a pedicle valve, X 1, paratype USNM 149795b; 5-8, anterior, ventral, posterior, and side views of another pedicle valve, x 1, paratype USNM 149795a. [Lenox Hills Formation (Ammonite Bed), USNM 715.] 9-12, Ventral, posterior, anterior, and side views of a pedicle valve, x 1, holotype USNM 149793a. [Lenox Hills Formation, USNM 707j.] Kozlowskia nasuta, new species: 13-16, Side, anterior, posterior, and ventral views, X 1, holotype USNM 149798; 17, 18, ventral and dorsal views of the holotype, X 2, showing the short anterior siphon and concentric trails; 19, 20, exterior and interior of the brachial valve of the holotype, X 1; 21, interior of the holotype, x 2, showing brachial ridges and occasional endospines; 22, 23, interior and posterior of the brachial valve of the holotype, X 3, showing cardinal process and ear baffles. [Neal Ranch Formation (bed 9 of Cooper), USNM 701a.] Kozlowskia kingi Stehli: 24-27, Ventral anterior, posterior, and side views of a large pedicle valve, X 1, hypotype USNM 149805a (for interior, see plate 314: figure 45); 28-31, posterior, anterior, ventral, and side views of another pedicle valve, x 1, hypotype USNM 149805c [Bone Spring Formation, USNM 728f.] 32-35, Ventral, side, anterior, and posterior views of a strongly alate pedicle valve, X 1, hypo- type USNM 149803d; 36-39, ventral, posterior, interior, and anterior views of a finely costellate specimen, X 1, showing the ear baffles, hypotype USNM 149803g; 40-43, dorsal, anterior, ventral, and posterior views, x 1, showing dorsal trails and a narrow median fold, hypotype USNM 149803a; 44-47, anterior tilted, ventral, posterior, and ventral views of a pedicle valve preserving one of the long halteroid spines, X 1, hypotype USNM 149803h; 48-51, side, anterior, ventral, and posterior views of a completely costellate pedicle valve, X 1, hypotype USNM 149803i; 52-55, anterior, posterior, side, and ventral views of a costellate specimen with some of its spines, X 1, hypotype USNM 149803J; 56-58, ventral, side, and dorsal views of a complete specimen, x 1, showing trails of the brachial valve, hypotype USNM 149803k. [Bone Spring Formation, USNM 728c] NUMBER 19 1543 PLATE SlS.-Kozlowskia 1544 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 314 Kozlowskia Kozlowskia subsphaeroidalis, new species: 1-4, Anterior, ventral, side, and dorsal view of a pedicle valve, X 1, paratype USNM 149797k; 5-8, side, ventral, anterior, and dorsal views of a complete specimen, X 1, paratype USNM 149797b; 9-12, dorsal, ventral, anterior, and side views of a com- plete specimen, x 1, holotype USNM 149797a; 13, dorsal view of the holotype, X 2,; 14-16, in- terior, X 1, interior and posterior, x 2, of a small brachial valve, paratype USNM 149797q; 17, interior of another brachial valve, x 1, paratype USNM 149797p; 18, 19, interior and postero- dorsal views of the preceding brachial valve, X 2, showing margin, septum and sparse endospines; 20, interior of the preceding, x 3, showing ear baffles and small cardinal process. [Skinner Ranch Formation (base), USNM 71 lp.] Kozlowskia kingi Stehli: 21-24, Ventral, posterior, anterior, and side views of a large, costellate pedicle valve, X 1, hypotype USNM 149803f; 25, 26, anterior, and partial side views of a broken specimen, X 1, showing the long endospines, hypotype USNM 149803-1; 27, ventral view of the preceding specimen, showing the large endospines, X 2; 28, another broken specimen, X 1, show- ing endospines, hypotype USNM 149803n; 29, dorsal view of a complete specimen, x 1, showing dorsal trails, hypotype USNM 149803m; 30-33, anterior, dorsal, interior, and tilted anterior views, X 1, showing the margin and trail, hypotype USNM 149803o; 34, 35, interior and side views of the preceding brachial valve, X 2, showing the marginal ridge, trail, brachial ridges, and ear baffles; 36-38, side, anterior, and interior views of another brachial valve, X 1, showing the trail and marginal rim, hypotype USNM 149803J; 39, 40, interior and posterodorsal views of the preceding brachial valve, X 2, showing the marginal ridge and cardinal process; 41, 42, side and interior views of a brachial valve with strong marginal ridge, X 1, hypotype USNM 149803q; 43, 44, interior and posterior views of the preceding brachial valve, X 3, showing cardinal process, ear baffles, and few endospines. [Bone Spring Formation, USNM 728c] 45, Interior of the pedicle valve, X 2, showing strong, fluted ear baffles, hypotype USNM 149805a (for exterior, see plate 313: figures 24-27) . [Bone Spring Formation, USNM 728f.] NUMBER 19 1545 PLATE 314,-Kozlowskia 1546 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 315 Hystriculina Hystriculina minima new species: 1-4, Dorsal, ventral, anterior, and side views of a complete specimen, X 1, holotype USNM 153898a; 5-8, side, posterior, ventral, and anterior views of a pedicle valve preserving one of the long halteroid spines, x 1, paratype USNM 153898b; 9-13, anterior, dorsal, posterior, ventral, and side views of a specimen stripped of its spines, x 1, para- type USNM 149773f; 14-18, ventral, side, anterior, posterior, and dorsal views of another stripped specimen, x 1, paratype USNM 149773d; 19, 20, interior and exterior of a brachial valve, X 2, paratype USNM 153898c; 21, posterior of the preceding specimen, X 3, showing the cardinal process; 22, 23, exterior and interior views of another brachial valve, X 2, paratype USNM 153898d. [Neal Ranch Formation (bed 4), USNM 701d.] Hystriculina pumila, new species: 24-28, Anterior, ventral, posterior, dorsal, and side views of a complete specimen, X 1, paratype USNM 149759c; 29, dorsal view of the preceding paratype, X 2; 30-34, anterior ventral, dorsal, side, and posterior views of another complete specimen, X 1, holotype USNM 149759b; 35, dorsal view of the holotype, x 2; 36, 37, ventral view of a small pedicle valve preserving many of its body spines, X 1, X 2, paratype USNM 149759J; 38, 39, ventral view of another pedicle valve retaining some of its spines, X 1, X 2, paratype USNM 149759k; 40, 41, ventral view of a third paratype retaining many of its spines, X 1, X 2, USNM 149759-1; 42, 43, interior and exterior of the brachial valve, X 2, paratype USNM 149759m; 44, posterodorsal view of the preceding brachial valve, x 3, showing the cardinal process; 45, 46, in- terior and exterior of another brachial valve, x 2, paratype USNM 149759n; 47, posterodorsal view of the preceding paratype, x 3, showing the cardinal process. [Skinner Ranch Formation (base), USNM 71 lp.] Hystriculina ventroplana, new species: 48-52, Anterior, ventral, side, dorsal, and posterior views of a complete specimen, x 1, paratype USNM 149777a; 53-57, dorsal, posterior, ventral, anterior, and side views of another complete specimen, x 1, holotype USNM 149777b; 66-70, side, ventral, anterior, dorsal, and posterior views of a paratype preserving some of its spines, X 1, USNM 149777c; 71, 72, ventral and dorsal views of the preceding specimen, X 2. [Neal Ranch Formation (upper 15 feet of bed 2 of P. B. King), USNM 701.] 58-61, Posterior, side, anterior and ventral views of a paratype, X 1, USNM 149783b; 62-65, side, posterior, and ventral, anterior views, X 1, of another paratype USNM 149783a. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701q.] NUMBER 19 1547 PLATE M5.-Hystriculina 1548 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 316 Bothrionia and Thamnosia Bothrionia nasuta, new species: 1-4, Ventral, dorsal, anterior, and side views, X 1, of the holotype USNM 149637a; 5, 6, ventral and dorsal views, X 2, of the holotype; 7-9, dorsal, ventral, and anterior views of a small, nonnasute specimen, x 1, paratype USNM 149637f; 10-12, ventral, an- terior, and dorsal views of a nasute specimen, x 1, paratype USNM 149637b. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] 13-16, Ventral, dorsal, anterior, and side views of a complete specimen, X 1, paratype USNM 153845. [Word Formation (China Tank Member), USNM 726r.] 17-20, Side posterior, anterior, and ventral views of a pedicle valve, X 1, paratype USNM 149639. [Word Formation (China Tank Member), USNM 713.] 21-23, Anterior, posterior, and ventral views of a nasute pedicle valve, X 1, paratype USNM 149635a; 24, 25, interior and exterior of the preceding specimen, x 2, showing strong marginal rim; 26, anterior of a pedicle valve which has not yet developed a nasute projection, x 1, para- type USNM 149635b. [Word Formation (Willis Ranch Member), USNM 706.] Bothrionia guadalupensis, new species: 27-29, Ventral, anterior, and side views of a nasute pedicle valve, X 1, paratype USNM 149628a; 30-33, anterior, side, dorsal, and ventral views of a complete specimen, x 1, paratype USNM 149628c; 34-37, ventral, dorsal, side, and anterior views of a specimen preserving both valves, x 1, holotype USNM 149628d; 38, 39, interior of the brachial valve of the holotype, X 1, X 2; 40, 41, interior and posterior views of the brachial valve of the holotype, X 3, showing cardinal process, breviseptum and large endospines; 42-45, ventral, side, anterior, and dorsal views of a paratype with pedicle valve partially broken away, x 1, USNM 149628b; 46, dorsal view, X 1.5, of the preceding specimen; 47, laterally tilted view of the preced- ing, X 2, showing the breviseptum and endospines, X 2; 48-50, anterior, ventral, and side views of a pedicle valve, x 1, paratype USNM 149628e; 51, dorsal view, X 1, of a paratype preserving the brachial valve, USNM 149628L [Cherry Canyon Formation (Getaway Member), USNM 728.] Thamnosia phragmophora, new species: 52-56, Side, posterior, anterior, dorsal, and ventral views of a complete specimen, X 1, paratype USNM 153847. [ Word Formation (Appel Ranch Member), USNM 719z.] NUMBER 19 1549 PLATE 316.-Bothrionia and Thamnosia 1550 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 317 Bothrionia Bothrionia nasuta, new species: 1-3, Anterior, posterior, and side views of a pedicle valve, X 1, paratype USNM 149636a; 4, ventral view of the preceding specimen, x 2; 5, interior of the preceding specimen showing the inner margin, x 1; 6, 7, exterior and interior of a brachial valve, X 1, paratype USNM 149636b; 8, interior of the preceding specimen, X 2, showing the large endospines; 9, 10, interior and posterior of the preceding specimen, X 3, showing the cardinal process and breviseptum, [Word Formation (lens between Willis Ranch and Appel Ranch mem- bers) , USNM 706.] Bothrionia pulchra, new species: 11-14, dorsal, anterior, anterior, and side views, X 1, of the holotype, USNM 149631; 16, 16, ventral and dorsal views of the holotype, X 2, [Cherry Canyon Formation (Getaway Member), USNM 732.] 17, 18, Side and interior views of a pedicle valve, X I, paratype USNM 149630. [Cherry Canyon Formation (Getaway Member), USNM 730.] Bothrionia transversa, new species: 19-22, Interior, side, anterior, and posterior views of a pedicle valve, X 1, paratype USNM 149646h; 23-26, anterior, dorsal, side, and posterior views of a com- plete specimen, X 1, paratype USNM 149646e; 27-30, dorsal, posterior, anterior, and side views of another complete specimen, x 1, paratype USNM 149646b; 31-33, ventral, dorsal, and pedicle valve interior, x 1, of the holotype USNM 149643; 34, interior of the pedicle valve of the holo- type, X 2, showing peripheral rim; 35, interior of the brachial valve of the holotype, X 1; 36, 37, interior and posterior of the brachial valve of the holotype, X 3, showing breviseptum, endospines and cardinal process. [Word Formation (Appel Ranch Member), USNM 715i.] 38-41, Side, posterior, anterior, and ventral views of a pedicle valve, X 1, paratype USNM 149641a; 42, interior of the preceding pedicle valve, X 1; 43-46, dorsal, side, anterior, and pos- terior views of a complete specimen, X I, paratype USNM 149641c; 47, dorsal view of the preced- ing paratype, X 2. [Word Formation (Appel Ranch Member), USNM 706b.] 48-50, Ventral, side, and posterior views of a pedicle valve, X 1, paratype USNM 153846. [Word Formation (Appel Ranch Member), USNM 719z.] Bothrionia transversa, new species: 51-54, Anterior, side, ventral, and posterior views of a poorly preserved specimen, X 1, figured specimen YPM 11733. [Word Formation (Appel Ranch Member), R. E. King locality 247.] NUMBER 19 1551 PLATE 317.-Bothrionia 1552 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 318 Oncosarina and Bothrionia Oncosarina rotunda new species: 1-4, Dorsal, side, ventral and anterior views, X 1, of the holo- type USNM 149819d; 5, dorsal view of the holotype, x 2; 6-8, ventral, side, and posterior views of a well preserved pedicle valve, X 1, paratype USNM 149819a; 9, ventral view of the preceding paratype, X 2; 10-13, dorsal, ventral, side, and posterior of another complete specimen, X 1, paratype USNM 149819b; 14, dorsal view of the preceding specimen, X 2; 15-18, ventral, anterior, side, and dorsal views of a young specimen, x 1, paratype USNM 149819J; 19, dorsal view of the preceding paratype, X 2, showing the strong concentric wrinkles on the dorsal valve; 20-23, posterior, side, dorsal, and ventral views of another young paratype, x 1, USNM 149819g; 24, dorsal view of the preceding specimen, X 2; 25, 26, dorsal view of a specimen, X 1, X 2, showing the large cardinal process, paratype USNM 1498I9p. [Skinner Ranch Formation (Decie Ranch Member), USNM 714t.] Bothrionia transversa, new species: 27-30, Side, anterior, ventral, and posterior views of a pedicle valve, X 1, paratype USNM 153848a; 31-34, side, posterior, anterior, and ventral views of another large pedicle valve, x 1, paratype USNM 153848b; 35, 36, interior and posterior views of a brachial valve, X 2, showing the brachial ridges and endospines, paratype USNM 153848c; 37, 38, posterior and interior views of another brachial valve, x 2, showing the same features as the preceding specimen, paratype USNM 153848d; 39, 40, interior, x 2, and posterior, X 3, of a brachial valve, showing the cardinal process, paratype USNM 153848c [Word Formation (Appel Ranch Member, USNM 722t.] 41-44, Posterior, ventral, side, and anterior views of a pedicle valve, X 1, paratype USNM 153849a; 45, interior of a brachial valve, x 1, paratype USNM 153849b; 46, 47, interior and posterior of the preceding specimen, X 2, showing endospines; 48, posterior view of the preced- ing paratype, X 3, showing the cardinal process; 49, 50, interior of another brachial valve showing breviseptum and endospines, X 1, X 2, paratype USNM 153849c; 51, posterior view of the preceding paratype, X 3, showing the cardinal process. [Word Formation (Appel Ranch Member), USNM 719z.] 52-54, Posterior, ventral, and side views of a complete specimen, x 1, paratype USNM 153850a; 55, dorsal view of the preceding specimen, X 2, showing the brachial valve in place; 56, 57, interior of a brachial valve, X 2, X 3, showing features of the interior much thickened, paratype USNM 153850b. [Word Formation (Appel Ranch Member), USNM 715i.] NUMBER 19 1553 PLATE 318.-Oncosarina and Bothrionia 1554 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY' PLATE 319 Costispinifera Costispinifera rugalula (Girty): 1, Ventral view of a large pedicle valve with some of its body spines, x 1, hypotype USNM 149708b; 2, ventral view of another pedicle valve, x 1, preserving halteroid and body spines, hypotype USNM 149708a; 3-7, ventral, dorsal, side, posterior, and anterior views of a young adult preserving many of its halteroid spines, X 1, hypotype USNM 149708c; 8, 9, dorsal and ventral views of an immature specimen, X 1, paratype USNM 149715J; 10-13, dorsal, ventral, side, and posterior views of another young specimen, X 1, hypotype USNM 149715h; 14-17, ventral, dorsal, posterior, and side views of a young specimen, X 1, showing strong concentric wrinkles, hypotype USNM 149715g; 18-20, side, posterior, and dorsal views of another young adult, X 1, hypotype USNM 149715f; 21-23, ventral, dorsal and posterior views of a young adult, X 1, hypotype USNM 149715e; 24-27, posterior, side, dorsal, and ventral views of a full grown adult, X 1, hypotype USNM 149715c; 28-31, anterior, dorsal, ventral, and side views of a large adult, x 1, hypotype USNM 149715a; 32-35, dorsal, side, ventral, and posterior views of small adult, x 1, hypotype USNM 153862a; 36-39, posterior, ventral, side, and dorsal views of an average adult, X 1, hypotype USNM 153862c; 40-43, ventral, posterior, side, and dorsal views of an adult, x 1, hypotype USNM 153862b; 44, ventral view of a young specimen with strong concentric wrinkles, X 2, hypotype USNM 153863d; 45, ventral view of another young specimen, X 2, showing the strong concentric wrinkles, hypotype USNM 153863b; 46, ventral view of an- other youthful specimen, x 2, hypotype USNM 153863c; 47, young specimen, ventral view preserving most of its body spines, X 2, hypotype USNM 153863a; 48-50, interior, X 1, X 2, and side view, X 2, of a brachial valve with long endospines, hypotype USNM 153863f; 51-53, exterior X 1, X 2, and posterior, X 2, of a brachial valve, showing the numerous protective spines, hypotype USNM 149708d; 54-56, interior, X 1, posterior, X 2, and interior, X 2, of a brachial valve with thickened interior details, hypotype USNM 149708c [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1555 PLATE S19.-Costispinifera 1556 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 320 Costispinifera Costispinifera costata (R. E. King): 1, Ventral view of a large pedicle valve preserving some of its halteroid and body spines, X 1, hypotype USNM 149702a; 2, ventral view of another pedicle valve with some of the body spines preserved, x 1, hypotype USNM 149702b; 3, ventral view of a small pedicle valve, X 1, hypotype USNM 149702c; 4, ventral view of a pedicle valve preserving many of its body spines, X 1, hypotype USNM 149702d; 5, ventral view of a young pedicle valve with initial spine ring, x 1, hypotype USNM 149702e; 6-10, dorsal, side, ventral, posterior, and an- terior views of an adult, X 1, hypotype USNM 149703o; 11, dorsal view of another, complete specimen, X 1, hypotype USNM 149703a; 12-16, posterior, anterior, side, ventral, and dorsal views of a complete specimen, x I, hypotype USNM 149703i; 17-21, anterior, ventral, dorsal, side, and posterior views of a small adult, x 1, hypotype USNM 149703b; 22-26, posterior, ventral, anterior, dorsal, and side views of a large adult, X 1, hypotype USNM 149703d; 27-29, posterior, interior, and side views of a dorsal valve, x 1, hypotype USNM 153864a; 30, interior of the pre- ceding brachial valve, X 2, showing the long endospines; 31-33, posterior, side, and interior views of another brachial valve, x 1, showing long endospines, hypotype USNM 153864c; 34, interior of the preceding specimen, X 2; 35, 36, dorsal view of a brachial valve, X 1, X 2, show- ing numerous spines, hypotype USNM 153864d; 37, 38, exterior of another brachial valve preserv- ing the protective spines, X 1, X 2, hypotype USNM 153864e; 39, 40, exterior of an alate brachial valve preserving the protective spines, X 1, X 2, hypotype USNM 153864f; 41, dorsal view of another alate brachial valve, X 1, showing protective spines, hypotype USNM 153864g. [Word Formation (Willis Ranch Member), USNM 706.] 42-44, Posterior, side, and ventral views of a large pedicle valve, X 1, figured specimen, USNM 153865. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] Costispinifera cf. C. costata (R. E. King): 45-48, Side, dorsal, ventral, and posterior views of a large adult, X 1, figured specimen USNM 153866. [Road Canyon Formation, USNM 721 j.] 49-51, Ventral, side, and posterior views of an unusually large pedicle valve, X 1, figured speci- men, USNM 153867. [Word Formation (Willis Ranch Member), USNM 731m.] NUMBER 19 1557 PLATE 320,-Costispinifera 1558 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 321 Costispinifera Costispinifera rugatula (Girty) : 1, Interior of a well developed brachial valve, X 1, hypotype USNM 153868g; 2, interior of another well developed brachial valve, X 4, showing endospines, breviseptum, and cardinal process, hypotype USNM 153868d; 3, side views of the preceding specimen, x 2, showing cardinal process and endospines; 4, dorsal view of the cardinal process of the preceding specimen, x 4; 5, 6, ventral view of an immature specimen, X 1, X 2, showing the initial attachment rings, hypotype USNM 153869. [Word Formation (China Tank Member), USNM 706c] 7, 8, Ventral view of two pedicle valves, X 1, hypotypes USNM 153870b, c; 9, interior of the brachial valve, x 1, hypotype USNM 153870a. [Word Formation (China Tank Member), USNM 732s.] Costispinifera costata (R. E. King): 10-13, Side, ventral, anterior, and dorsal views, X 1, hypotype USNM 124150a; 14, dorsal view, showing the beak and ear baffles of the pedicle valve, X 2, hypo- type USNM 124150b; 15-17, side, interior, and anterior views of a brachial valve, X 2, hypotype USNM 124151b; 18, exterior of a brachial valve, showing numerous spines and their bases, X 2, hypotype USNM 153871c; 19, ventral view of a small individual, x 1, showing the halteroid spines, hypotype USNM 153871a; 20, ventral view of another pedicle valve, X 1, showing body spines, hypotype USNM 153871b; 21, 22, ventral view of an immature specimen, X 1, X 2, showing attachment rings, hypotype USNM 153872a; 23, 24, ventral view of another immature pedicle valve, X 1, X 2, hypotype USNM 153872b; 25, 26, ventral view of an immature pedicle valve larger than the preceding but still retaining the attachment ring, X 1, X 2, hypotype USNM 153872c; 27, ventral view of a very young specimen, x 2, showing attachment rings, hypo- type USNM 153872d; 28, same view of another immature pedicle valve, X 2, hypotype USNM 153872c; 29, ventral view of a pedicle valve, immature but larger than the preceding and showing development of halteroid spines, X 2, hypotype USNM 153872f. [Word Formation (Willis Ranch Member), USNM 706.] NUMBER 19 1559 PLATE S21.-Costispinifera 1560 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 322 Elliottella Elliottella transversalis (Stehli): 1-4, Interior, X 1, and side, interior, and posterior views, X 2, showing brachial ridges, hypotype USNM 153883e; 5, 6, interior of a brachial valve, X 1, X 2, showing the breviseptum and endospines, hypotype USNM 153883b; 7-10, interior, x I, side, interior, and posterior views, X 2, of another brachial valve, showing breviseptum and endo- spines, hypotype USNM 153883a; 11-14, interior, X 1, interior, side, and posterior views, X 2, showing details of the interior, hypotype USNM 153883c; 15, posterior of a brachial valve, X 2, showing the cardinal process, hypotype USNM 153883d; 16, 17, ventral view of two pedicle valves preserving some of their spines, X 1, hypotypes USNM 153883f, g; 18, ventral view of an excep- tionally well preserved pedicle valve, showing halteroid and body spines, X 1, hypotype USNM 153883J; 19, 20, ventral view of an immature specimen preserving the initial attachment rings, X 1, X 2, hypotype USNM 153883k; 21, 22, ventral view of another immature specimen with attachment rings, X 1, X 2, hyptotype 153883-1; 23, 24, ventral view, of an immature speci- men, X 1, X2, larger than the preceding and showing early body spines, hypotype USNM 153883m; 25, 26, ventral view of two immature pedicle valves with long spines, X 1, hypotypes USNM 153883h, i; 27-31, dorsal, anterior side, posterior, and ventral views of a complete specimen shorn of its spines, X 1, hypotype USNM 153883n; 32-36, side, anterior, posterior, dorsal, and ventral views of a complete specimen, x 1, hypotype USNM 153883p; 37-39, ventral, side, and posterior views, X 2, of the preceding hypotype; 40-43, side, ventral, posterior, and anterior views of a pedicle valve, x 1, hyptoype USNM 153883o. [Bone Spring Formation, USNM 728f.] NUMBER 19 1561 PLATE S22.-Elliottella 1562 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 323 Elliottella Elliottella minima (Stehli) : 1-5, Ventral, posterior, anterior, dorsal and side views, X 1, hypotype USNM 152707b; 6-10, posterior, ventral, side, dorsal, and anterior views of a complete specimen, X 1, hypotype USNM 152707d; 11-13, ventral, side, and posterior views of a pedicle valve having some of its spines, X I, hypotype USNM 152707J; 14-17, ventral, anterior, side, and posterior views of another specimen with some of its spines, X 1, hypotype USNM 152707k; 18, 19, interior of the brachial valve, X 1, X 2, hypotype USNM 152707-1; 20, posterior of the preceding speci- men, X 3, showing the cardinal process; 21, 22, interior of the brachial valve, X 1, X 2, hypotype USNM 152707m; 23, 24, interior, x 2, and posterior, X 3, showing the cardinal process, hypotype USNM 152707n. [Bone Spring Formation, USNM 728c] Elliottella multicostata, new species: 25-27, Posterior, ventral, and anterior views of a specimen with spines, X 1, paratype USNM 153882a; 28-30, anterior, posterior, and ventral views of an- other spiny specimen, X 1, holotype USNM 153882d; 31-33, anterior, ventral, and posterior views of a spiny paratype, x 1, USNM 153882c; 34-36, anterior, ventral, and posterior views of a small, spiny pedicle valve, X 1, paratype USNM 153882b; 37-39, posterior, ventral, and anterior views of a small spiny specimen, x 1, paratype USNM 153882e; 40, 41, ventral view of an im- mature specimen, x 1, X 2, paratype USNM 153882f; 42, 43, ventral view of another immature pedicle valve, X 1, X 2, paratype USNM 153882h; 44, ventral view of an immature pedicle valve, X 1, paratype USNM 153882g; 45, 46, ventral view of two immature specimens, X 2, showing initial attachment ring and early body spines, paratypes USNM 151589a, b; 47-50, interior X 1, X 2, and side and posterior, X 2, views of the brachial valve, paratype USNM 153882k; 51-54, interior, X 1, X 2, and side and posterior views, X 2, of another brachial valve, showing the cardinal process and scattered endospines, paratype USNM 153882J; 55-58, interior, X 1, X 2, and side and posterior views, X 2, showing endospines and cardinal process, paratype USNM 1538821- [Bone Spring Formation, USNM 728h.] NUMBER 19 1563 PLATE S2S.-Elliottella 1564 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 324 Oncosarina Oncosarina spinicostata Cooper and Grant: 1-3, Interior, X 1, X 2, and posterior, X 2, views of a brachial valve, showing cardinal process and adductor platform, hypotype USNM 153884a; 4-6, interior, X 1, X 2, and posterior, X 2, views showing adductor platform, breviseptum and endo- spines, hypotype USNM 153884c; 7-9, interior, x 1, X 2, and posterior, x 2, views, showing cardinal process, hypotype USNM 153884b; 10-14, posterior, side, ventral, and anterior views, X 1, and ventral view X 2, showing halteroid spines, hypotype USNM 153884d; 15-18, side, anterior, and ventral views, X 1, and ventral view, X 2, of another spiny pedicle valve, hypotype USNM 153884e; 19-22, side, ventral, and anterior views, x 1, and ventral view, x 2, of a pedicle valve with well preserved spines, holotype USNM 149824 (= 153884f); 23-27, side, ventral, anterior, posterior, and dorsal views of a complete specimen with halteroid spines, X 1, hypotype USNM 153884h; 28-32, side, posterior, anterior, dorsal, and ventral views of the preceding hypotype, X 2; 33-36, anterior, side, ventral, and posterior views of a specimen shorn of its spines, X 1, hypotype USNM 149825a. [Skinner Ranch Formation (Poplar Tank Member), USNM 707ha.] 37-40, Dorsal, ventral, posterior, and side views of a complete specimen from which the spines have been stripped, X I, hypotype USNM 149823b; 41, interior of a brachial valve, X 2, hypotype USNM 153885a; 42, interior of another specimen preserving part of the pedicle valve and the brachial valve interior, X 2, hypotype USNM 153885b. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707-1.] NUMBER 19 1565 PLATE 324,-Oncosarina 1566 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 325 Hystriculina and Elliottella Hystriculina convexa, new species: 1-5, Anterior, side, ventral, dorsal, and posterior views of a complete specimen, x 1, holotype USNM 149764a; 6-8, ventral, side, and dorsal views of the holotype, x 2; 9-13, ventral, side, posterior, anterior, and dorsal views of another complete speci- men, X 1, paratype USNM 149764b; 14-17, ventral, dorsal, posterior, and side views of a complete specimen, X I, paratype USNM 149765d; 18, 19, dorsal and ventral views of the preceding speci- men, x 2; 20, dorsal view of a complete specimen shorn of its spines, X 2, paratype USNM 149765e; 21, 22, interior, X 2, and posterior, X 3, views of the brachial valve, showing cardinal process, ear baffles, and endospines, paratype USNM 149764c; 23, 24, interior, X 2, and posterior, X 3, views of another brachial valve, paratype USNM 149764d. [Neal Ranch Formation (bed 4), USNM 701d.] Elliottella varicostata, new species: 25-29, Dorsal, anterior, ventral, side, and posterior of a complete specimen, X 1, paratype USNM 152706e; 30-33, side, ventral, anterior, and posterior views of a pedicle valve, x 1, paratype USNM 152706c; 34-37, side, posterior, anterior, and ventral views of a large pedicle valve, X 1, paratype USNM 152706a; 38-42, posterior, dorsal, side, ventral, and anterior views, X 1, holotype USNM 152706n; 43, 44, ventral view of a speci- men preserving some of its spines, X 1, X 2, paratype USNM 152706o; 45, interior of a mold of the brachial valve, showing muscle scars, brachial ridges and endospines, X 2, paratype USNM 152706q; 46, 47, interior of two brachial valves, X 2, showing brachial ridges and muscle scars, paratypes USNM 152706r, s. [Skinner Ranch Formation (base), USNM 705a.] 48-52, Posterior, ventral, dorsal, anterior, and side views of a complete specimen, X 1, para- type USNM 153881a; 53-57, side, posterior, anterior, pedicle, and dorsal views of a specimen, showing some of its spines, X 1, paratype USNM 153881b; 58-60, ventral, dorsal and side views of the preceding paratype, X 2. [Skinner Ranch Formation (base), USNM 724p.] NUMBER 19 1567 PLATE 325.-Hystriculina and Elliottella 1568 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 326 Echinauris Echinauris bella, new species: 1-4, Exterior, interior, anterior, and posterior views, X 2, small dorsal valve, paratype USNM 149621v; 5, dorsal view, X 2, small shell, paratype USNM 149621w; 6, dorsal view, x 2, small shell with spines, paratype USNM 149621x; 7-9, ventral and dorsal views, x 2, and dorsal view, X 1, juvenile paratype with long spines, USNM 149621y; 10-13, side, exterior, interior, and posterior views, X 2, dorsal valve with cardinal process and median sep- tum, paratype USNM 149621z; 14-15, dorsal views, X 1, X 2, small paratype with long divergent lateral spines, paratype USNM 149621a'; 16-19, exterior, interior, side, and posterior views, X 2, small dorsal valve, paratype USNM 149621b'; 20-22, stereo-pair, X 2, of dorsal view (figure 20), dorsal view x 1, and side view, X 2, small complete shell, paratype USNM 149621C; 23-25, dorsal views, X I, X 2, and ventral view, x 3, complete shell, paratype USNM 149621d'; 26-27, dorsal views of ventral valve, X 2, X 1, showing interior, paratype USNM 149621e'; 28-30, dorsal views, X 3, X 1, and ventral view, X 2, shell with spines and attached epifauna, paratype USNM 149621f; 47-50, exterior, interior, posterior, and side views, X 2, dorsal valve paratype USNM 149621g'; 51-54, exterior, interior, posterior, and side views, X 2, dorsal valve, paratype USNM 149621h'. 55-58, exterior, interior, side, and posterior views, X 2, dorsal valve, paratype USNM 14962H'. [Road Canyon Formation, USNM 707c] 31-34, Interior and ventral, X 1, X 3, ventral exterior, X 1, X 3, and side views, X 3, para- type USNM 154772a; 45-46, interior and exterior views, X 3, dorsal valve, paratype USNM 154772b. [Cathedral Mountain Formation, USNM 702.] 35-36, Ventral views, X 3, X 1, ventral valve, paratype USNM 154773a; 37-41, dorsal views, X 3, X 1, ventral views, x 3, X 1, and side view, x 3, holotype USNM 154773b; 42-44, ventral view, x 2, interior views, X 3, X 1, ventral valve, paratype USNM 154773c [Road Canyon Formation, USNM 702c] NUMBER 19 1569 PLATE 326.-Echinauris 1570 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 327 Echinauris Echinauris crassa, new species: 1-4, Interior views, X 1, X 3, and ventral views, X 2, X 3, nepionic ventral valve, paratype USNM 154774a; 5-9, dorsal and anterodorsal views, X 1, X 2, and ventral views, X 2, X 3, small gaping shell, paratype USNM 154774b. [Cathedral Mountain Formation (Wedin Member), USNM 723v.] 10-13, Dorsal views, X 2, X 1, and ventral and side views, X 2, paratype USNM 152708b; 14-18, ventral, dorsal, and side views, X 1, X 2, paratype shell USNM 152708d; 19-21, dorsal and ventral views, X 1, X 2, paratype shell with broken spines, USNM 152708c; 22-28, ventral, interior, dorsal, side, and dorsal interior views, X 1, X 2, adult holotype shell, USNM 152708a; 29, dorsal view, x 2, shell with two crinkled spines, paratype USNM 152708f; 30-32, interior and ventral views, X 2, ventral valve, paratype USNM 152708c [Road Canyon Formation (base), USNM 703a.] 33-36, Ventral and side views, X 1, X 2.25, ventral valve with long spines, paratype USNM 154775a. [Road Canyon Formation, USNM 721y.] NUMBER 19 1571 PLATE 327.-Echinauris 1572 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 328 Echinauris Echinauris interrupta, new species: 1-3, Ventral views, X 1, X 2, X 3, nepionic ventral valve, paratype USNM 152710J; 4-9, interior and exterior views, X 1, X 2, X 3, nepionic ventral valve with attachment ring, paratype USNM 152710k; 10-12, interior views, X 1, X 2, X 3, nepionic ventral valve with remnants of attachment ring, paratype USNM 1527101; 13-16, ven- tral views, X 1, X 2, X 3, side view, x 3, small ventral valve with very long spines, paratype USNM 152710-1; 17-22, ventral, dorsal, and side views, X 1, X 3, adult paratype shell, USNM 152710a; 25-28, ventral, dorsal and side views, X 1, X 2, adult paratype with attached coral, USNM 152710b; 29-33, dorsal, ventral and side views, X 1, X 2, adult holotype USNM 152710c [Neal Ranch Formation, USNM 701d.] 23-24, Ventral and side views, X 2, calcareous paratype without spines, USNM 152709a. [Lenox Hills Formation, USNM 715.] NUMBER 19 1573 PLATE 328.-Echinauris 1574 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 329 Echinauris Echinauris irregularis, new species: 1-6, Ventral views in stereo, X 1, posterior, side, dorsal, and ventral views, X 2, dorsal views in stereo, X 1, adult holotype, USNM 154776a. [Cathedral Mountain Formation (base), USNM 702b.] 7-11, Dorsal views, X 2, X 1, posterior, anterior, and side views, X 2, adult paratype USNM 154788a. [Road Canyon Formation (base), USNM 703a.] 12-18, Ventral and interior views, X 1, X 2, posterior, anterior, and side views, X 2, ventral valve, paratype USNM 154779c [Cathedral Mountain Formation, USNM 721u.] 19-24, Interior views, X 2, X 1, dorsal, posterior, side, and interior views, X 2, ventral valve, paratype USNM 154786a. [Cathedral Mountain Formation (base), USNM 702.] NUMBER 19 1575 PLATE 329.-Echinauris 1576 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 330 Echinauris Echinauris irregularis, new species: 1-2, Ventral views, X 2, X 4, nepionic ventral valve with attachment ring, paratype USNM 154786c; 5, ventral view, X 4, nepionic ventral valve with attachment ring and open umbo, paratype USNM 154786d; 18, ventral view, X 4, spiny nepionic ventral valve with attachment ring, paratype USNM 154786f; 22-24, ventral view, X 4, interior views, X 2, X 4, nepionic ventral valve with attachment ring, paratype USNM 154786e; 30-31, stereo-pair, X 1, spiny juvenile ventral valve, side view, x 3, paratype USNM 154786g. [Cathedral Mountain Formation (base), USNM 702.] 3-4, Interior views, X 2, X 4, nepionic ventral valve with attachment ring, paratype USNM 154776b. [Cathedral Mountain Formation (base), USNM 702b.] 6-9, Ventral and interior views, X 2, X 4, nepionic ventral valve, paratype USNM 154787a; 17, dorsal view, x 2, nepionic shell with long spines, paratype USNM 154787b; 25, dorsal view, x 1, adult paratype shell, USNM 154787c; 34-36, dorsal views, X 2, X 1, ventral view, x 2, adult shell with dorsal spines, paratype USNM 154787d. [Road Canyon Formation, USNM 702c] 10, Ventral view, x 1, juvenile ventral valve, paratype USNM 154777f; 32, 33, dorsal views, X 1, X 3, spiny shell with dorsal spines, paratype USNM 154777g; 39-43, posterior, ventral, side, and interior views, X 2, X 1, ventral valve paratype USNM 154777h. [Cathedral Mountain Formation (base), USNM 702un.] 11-12, Ventral views, X 1, X 3, nepionic ventral valve, paratype USNM 154778a; 13-14, nepionic ventral valve, X 1, X 3, paratype USNM 154778b; 15-16, ventral views, X 1, X 3, nepionic ventral valve with attachment ring, paratype USNM 154778c. [Road Canyon Formation, USNM 703d.] 19, Interior view, x 2, juvenile ventral valve with attachment ring, paratype USNM 154779a; 20, dorsal view, X 1, young adult shell, paratype USNM 154779J; 21, interior view, X 1, young adult ventral valve, paratype USNM 154779k. [Cathedral Mountain Formation, USNM 721u.] 26-27, Dorsal views, X 2, X 1, young adult shell, paratype USNM 154788b; 28-29, interior views, x 1, X 2, spiny ventral valve, paratype USNM 154788c [Road Canyon Formation (base), USNM 703a.] 37-38, Ventral and side views, X 2, adult ventral valve with crinkly spine, paratype USNM 154780a. [Road Canyon Formation, USNM 724b.] NUMBER 19 1577 PLATE 330.-Echinauris 1578 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 331 Echinauris Echinauris irregularis, new species: 1-3, Interior views, X 1, X 2, and posterior view, X 2, nepionic ventral valve with attachment ring, paratype USNM 154777a; 4, ventral view, X 2, juvenile ventral valve, paratype USNM 154777b; 5-7, ventral view, X 2, interior views, X 1, X 2, juvenile paratype ventral valve, USNM 154777c; 8-9 interior views, X 1, X2, juvenile ventral valve, paratype USNM 154777d; 12-13, ventral and posterior views, X 2, juvenile ventral valve with long lateral spines, paratype USNM 154777c [Cathedral Mountain Formation, USNM 702un.] 10, Ventral view, X 2, juvenile ventral valve with attachment spines, paratype USNM 154779d; 11, dorsal view, x 1, adult shell, paratype USNM 154779f; 29, interior view, X 2, of the dorsal valve of a young individual, showing adductor platform, paratype USNM 154779e; 30, ex- terior view, X 2, dorsal valve tilted posteriorly to show end of cardinal process, paratype 154779g; 31, interior view, X 2, dorsal valve with muscle platforms, median septum, and cardinal process, paratype USNM 154779h; 32, interior views, X 2, dorsal valve showing muscle platforms, brachial ridges, endospines, taleolae and bifid cardinal process, paratype USNM 154779L [Cathedral Mountain Formation, USNM 721u.] 14-17, Ventral view, x 4 (stereo-pair), dorsal view, X 2, X 4 (stereo-pair), and side view, X 4, juvenile shell with attachment ring, paratype USNM 154786b. [Cathedral Mountain Forma- tion (base), USNM 702.] 18-22, Dorsal and ventral views, X 3, X 1, and side view, X 3, juvenile shell with healed interruption in growth and with remnant of attachment object at beak, paratype USNM 154781a. [Cathedral Mountain Formation (base), USNM 702a.] 23-27, Ventral, posterior, and side views, X 2, and interior view, X 1, X 2, ventral valve, paratype USNM 154787c [Road Canyon Formation, USNM 702c] 28, Interior view, x 2, spiny ventral valve with silicified sediment attached to spines, paratype USNM 154782a. [Road Canyon Formation, USNM 726z.] 33, 34, Interior and exterior views, X 2, dorsal valve with endospines and exospines, paratype USNM 154789a. [Cathedral Mountain Formation (base) USNM 703b.] NUMBER 19 1579 PLATE SSI.-Echinauris 1580 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 332 Echinauris Echinauris parva, new species: 1-3, Dorsal views, x 1, X 2, and ventral view, X 2, juvenile paratype, USNM 152718e; 4, interior view, X 2, dorsal valve, paratype USNM 154834a; 5-11, dorsal and ventral views, X 1, X 2, and posterior, side, and posteroventral views, X 2, adult paratype USNM 154834b; 12-16, dorsal views, X 2, X 1, and ventral, side, and posterior views, X 2, adult paratype USNM 154834c; 17, ventral view, x 2, young paratype USNM 154834d; 18-19, dorsal and ventral views, X 2, young adult paratype USNM 154834e; 20-24, ventral view in stereo, X 2, dorsal views, X 1 and X 2, side and posterior views, X 2, adult holotype USNM 154834L [Road Canyon Formation, USNM 716x.] Echinauris irregularis, new species: 25-29, Interior, X 2, X 1, and posterior, side, and anterior, X 2, views, ventral valve with long spines, paratype USNM 154777L [Cathedral Mountain Formation (base) USNM 702un.] 30, Interior view, x 2, small dorsal valve, paratype USNM 154779b. [Cathedral Mountain Formation, USNM 721 u.] 31-32, Posterior and side views, x 2, dorsal valve, paratype USNM 154781b. [Cathedral Moun- tain Formation, USNM 702a.] NUMBER 19 1581 PLATE SS2.-Echinauris 1582 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 333 Echinauris (All hypotypes unless otherwise stated) Echinauris lateralis Muir-Wood and Cooper: 1, Interior view, x 2, nepionic pedicle valve, USNM 149697P; 2, ventral view, x 4, nepionic pedicle valve with attachment ring, USNM 149697g'; 3-4, ventral views, x 4, x 2, pedicle valve with attachment ring, USNM 149697n; 5-6, interior views, X 2, X 4, nepionic pedicle valve USNM 149697o; 7, interior view, X 4, nepionic ventral valve with attachment ring, USNM 149697p; 8, exterior view, X 4, nepionic pedicle valve with attachment ring, USNM 149697w; 9-10, ventral views, X 1, X 2, pedicle valve with convergent cardinal spines, USNM 124052d; 11, ventral view, X 4, nepionic pedicle valve with attachment ring, USNM 149697q; 12, ventral view, x 2, juvenile pedicle valve USNM 149697r; 13-14, ventral views, x 2, X 1, spiny, pedicle valve, USNM 149697s; 15, dorsal view, X 2, brachial valve with epifaunal spat, USNM 149697t; 16-19, ventral, side, posterior, and interior views, X 1, pedicle valve, holotype USNM 124052a; 29, interior view, X 2, brachial valve with ear baffles, USNM 149697u; 30-34, interior views, X 2, X 1, posterior interior view, X 2, side interior views, X 1, X 2, brachial valve with large cardinal process, strong endospines, well defined septum and muscle areas, USNM 149697v. [Word Formation (Willis Ranch Member), USNM 706c] 20-23, Dorsal view, x 1.5, posterior, side, and ventral views, X 1, shell encrusted by small bryozoan colonies, USNM 149696b; 24-28, dorsal view, x 1.5, side, anterior, posteroventral, and ventral views, X 1, adult shell with long straight lateral spines, USNM 149696c. [Word Forma- tion (lens between Willis Ranch and Appel Ranch members) USNM 706b.] NUMBER 19 1583 PLATE SSS.-Echinauris 1584 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 334 Echinauris (All hypotypes unless otherwise stated) Echinauris lateralis Muir-Wood and Cooper: 1, Ventral view, X 1, ventral valve, USNM 149697a; 2-3, ventral views, X 1, X 1.5, ventral valve with attached spat of orthotetaceans, USNM 149697b; 4, ventral view, x 1, ventral valve with long lateral spine, USNM 149697c; 5, ventral view, X 1, ventral valve with circular borings, USNM 149697d; 6, interior view, X 1, ventral valve, USNM 149697e; 7-8, ventral and interior views, X 1, ventral valve with orthotetacean attached to lateral spines, USNM 149697f; 9-10, side and ventral views, X 1, ventral valve, USNM 149699 (see also plate 335: figure 36), 11, interior of a large pedicle valve, showing ear baffles, X 1, USNM 149697g; 14-15, interior views, X 2, X 1, articulated adult shell broken to show relationships of internal features, USNM 149698h; 16-21, interior views X 1, X 2, of dorsal valve (16, 17, facing; 18, 19, tilted posteriorly; 20, 21, side), USNM 149697J; 22-25, interior and side views, X 1, X 2, dorsal valve USNM 149697k; 26-31, interior, tilted, and side views, X 1, X 2, interior of dorsal valve, USNM 149697-1; 32-33, interior views, X 1 and X 2, small dorsal valve USNM 149697m. [Word Formation (Willis Ranch Member), USNM 706c] 12-13, Interior views, X 2, X 1, articulated shell broken to show interior features, USNM 149696a. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1585 PLATE SS4.-Echinauris 1586 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 335 Echinauris Echinauris circularis, new species: 1-6 Ventral views, X 1, X 2, X 3, interior views, X I, X 2, and side view, x 2, ventral valve, paratype USNM 152725c; 7-11, ventral, X 3, X 2, interior, X 1, X 2, and side, X 2, views, adult ventral valve, holotype USNM 152725b; 12-16, exterior, X 1, X 2, interior, X 3, and side, X 2, views, dorsal valve, paratype USNM 152725d; 17-21, in- terior, x 1, X 2, ventral, x 2, X 3, and side, X 2, views, ventral valve paratype USNM 152725e; 22-26, exterior, X 1, X 2, interior, X 3, X 2, and side, X 2, paratype USNM 152725f; 27-31, in- terior views, X 1, X 2, side, x 2, and exterior, X 2, X3, views, ventral valve, paratype USNM 152725g; 32-35, exterior, interior, and side, X 2, and interior, X 3, views, dorsal valve, paratype USNM 152725a. [Cathedral Mountain Formation, USNM 721u.] Echinauris lateralis Muir-Wood and Cooper (all hypotypes unless otherwise stated): 36, Dorsal view, x 1 (ventral valve also shown on plate 334: figure 11), USNM 149699; 37-38, ventral view, x 1, and side view, X 1.5, ventral valve with strong lateral spines, USNM 149697x; 39, in- terior view, X 1, dorsal valve, USNM 149697y; 40, interior view, X 2, dorsal valve tilted to show endospines, USNM 149697i; 42, anterodorsal view, X 2, dorsal valve with strong spines, paratype USNM 124052e; 43, exterior view, x 1, small dorsal valve, USNM 149697a'; 44, exterior view, X 1, 'small dorsal valve with attached spat of orthotetacean, USNM 149697b'; 45, exterior view, x 2, dorsal valve with convergent spines, USNM 149697c'; 46-47, interior views, X 2, X I, dorsal valve with healed injury at anterior margin, USNM 149697d'; 50, exterior view, X 1, dorsal valve with slender spines, USNM 149697e'; 51, exterior view, X 1, dorsal valve, USNM 149697z. [Word Formation (Willis Ranch Member), USNM 706c] 41, Interior view, x 1, brachial valve tilted to show cardinal process, USNM 149696d; 48-49, exterior views, x 1, X 2, dorsal valve with convergent lateral spines and attached small shells, USNM 149696c [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1587 PLATE 335.-Echinauris 1588 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 336 Echinauris Echinauris lappacea, new species: 1-3, Interior views, X 2, X 4, ventral view X 2, ventral valve, nepionic paratype USNM 154821a. [Road Canyon Formation, USNM 721 j-] 4-5, Ventral views, X 2, and X 1, ventral valve, juvenile paratype USNM 154823a; 6 ventral view, x 2, ventral valve, paratype USNM 154823b; 7, ventral view, X 2, ventral valve, paratype USNM 154823c; 11, ventral view, X 4, juvenile ventral valve, paratype USNM 154823d; 22-25, side and ventral views, X 2, dorsal views, X 2, X 1, adult paratype USNM 154823c [Road Canyon Formation, USNM 703d.] 8-10, Ventral view, X 2, and dorsal views, X 1, X 2, small shell, paratype USNM 154824a. [Cathedral Mountain Formation, USNM 726o.] 12, Interior view, x 2, dorsal valve, paratype USNM 154822a; 13-14, interior and side views, X 2, dorsal valve, paratype USNM 154822b; 15, interior view, x 2, dorsal valve with well defined brachial ridges and endospines, paratype USNM 154822c; 16-17, dorsal views, X 1, X 2, shell with robust and convergent dorsal spines, paratype USNM 152715c; 26-31, ventral, side, interior, posterior, anterior views, X 2, and interior view, x 1, ventral valve, holotype USNM 154822d. [Road Canyon Formation, USNM 707c] 18-21, Ventral, side, and interior views, X 2, and interior view, x 1, ventral valve, paratype USNM 154825a. [Bone Spring Formation (Cutoff Shale Member), AMNH 678.] NUMBER 19 1589 PLATE 336.-Echinauris 1590 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 337 Echinauris Echinauris liumbona, new species: 1-5, Interior and ventral views, X 1, X 2, and side view, X 2, pedicle valve with remnant of attachment ring, paratype USNM 154826a; 6-10, exterior and interior views, X 1, X 2, and side view, x 2, pedicle valve with convergent cardinal spines, paratype USNM 154826b; 11, interior view, X 2, pedicle valve showing internal spine openings, USNM 154826c; 12-17, posterior view, x 2, interior views, x 1, X 2, and side, anterior, and ventral views, x 2, pedicle valve, paratype USNM 154826d; 18-21, ventral views, X 2, X 1, and interior and side views, X 2, pedicle valve holotype USNM 152716o; 25-30, ventral and interior views, X 1, X 2, and posterior and side views, X 2, pedicle valve, paratype USNM 152716-1; 31-36, dorsal views, X 1, X 2, and ventral, side, posterior, and anterior views, X 2, paratype shell, USNM 154826c [Road Canyon Formation, USNM 703d.] 22-24, Interior views, X 1, X 2, facing and tilted to side, brachial valve showing cardinal process and muscle areas, paratype USNM 154827a. [Road Canyon Formation, USNM 721z.] NUMBER 19 1591 PLATE 337.-Echinauris 1592 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 338 Echinauris Echinauris magna, new species: 1-2, Ventral views, X 1, X 2, nepionic pedicle valve, paratype USNM 154828a; 3-4, interior views, X 1, X 2, nepionic brachial valve, paratype USNM 154828b; 5, ventral view, X 1, juvenile pedicle valve, paratype USNM 154828c; 9-14, interior views, X 1.5, X 1, and ventral view, X 1.5, posterior view, X 1, and side views, X 1, X 1.5, adult pedicle valve, paratype USNM 154828d; 22-23, interior and side views, X 2, brachial valve, para- type USNM 154828e; 24-26, interior views, X 1.5, X 1, and side view, X 1.5, brachial valve paratype USNM 154828f; 27, exterior view, X 1, brachial valve with numerous convergent spines, paratype USNM 154828g. [Park City Formation (upper Franson Member), USNM 760.] 6-8, Dorsal and ventral views, X 1, and side view, x 1.5, adult holotype shell, USNM 152717b; 15-18, ventral view, X 1.5, dorsal view, X 1, X 1.5, and side view, X 1.5, adult paratype shell, USNM 152717d; 19, interior view, X 2, pedicle valve, paratype USNM 152717i. [Park City Forma- tion (Franson Member), USNM 762.] 20-21, Ventral and side views, X 1.5, abraded adult shell, paratype USNM 154829a. [Phosphoria Formation, USNM 722a.] NUMBER 19 1593 PLATE SS8.-Echinauris 1594 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 339 Echinauris Echinauris productelloides, new species: 1-5, Exterior and interior views, x 1, X 2, and side view, X 2, juvenile pedicle valve, paratype USNM 152719e; 6-8, exterior views, X 1, X 2, and side view, x 2, juvenile pedicle valve, paratype USNM 152719i; 11-15, ventral, posterior, side, and interior views, X 2, interior view, X 1, adult pedicle valve, paratype USNM 152719h; 16-17, exterior and interior views, X 2, brachial valve, paratype USNM 152719J; 22-24, exterior, interior, and side views, X 2, brachial valve, paratype USNM 152719k; 25-28, ventral and side views, X 2, and interior views, X 1, X 2, pedicle valve, paratype USNM 152719-1; 29-33, ventral, posterior, and side views, X 2, and interior views X 1, X 2, pedicle valve, holotype USNM 152719g. [Cherry Canyon Formation (Getaway Member), USNM 732.] 9, Interior view, X 2, brachial valve, paratype USNM 154830a. [Cherry Canyon Formation (Getaway Member), AMNH 21.] 10, Interior view, x 2, brachial valve, paratype USNM 154831a; 18-21, ventral and interior views, X 1, X 2, and side view, X 2, pedicle valve, paratype USNM 154831b. [Cherry Canyon Formation (Getaway Member) , Moore 31.] 34-35, Dorsal views, X 1, X 2, paratype shell, USNM 154832a. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1595 PLATE 339.-Echinauris 1596 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 340 Echinauris Echinauris subquadrata, new species: 1-6, Ventral and interior views, X 1, X 1.5, and side and posterior views, X 1.5, silicified pedicle valve, holotype USNM 152722. [Neal Ranch Formation, USNM 701c] 7-10, Ventral and side views, X 1, X 2, calcareous pedicle valve, paratype USNM 152720. [Gaptank Formation, USNM 705h.] 11-14, Ventral and side views, X 1, X 2, calcareous pedicle valve, paratype USNM 154833a. [Gaptank Formation, USNM 701u.] 15-16, Ventral and side views, X 2, calcareous pedicle valve, paratype USNM 152721a; 17-22, dorsal and side views, X 2, and ventral and posterior views, X 1, X 2, calcareous natural shell cast, paratype USNM 152721b. [Gaptank Formation, USNM 701f.] NUMBER 19 1597 PLATE S40.-Echinauris 1598 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 341 Echinauris Echinauris venustula, new species: 1-2, Ventral views, X 1, X 2, nepionic pedicle valve, paratype USNM 154867a; 3-4, ventral views, X 1, X 2, nepionic pedicle valve, paratype USNM 154867c; 5-8, ventral views, X 1, X 2, dorsal and side views, X 2, nepionic shell with convergent cardinal spines, paratype USNM 154867b; 9-12, ventral views, X 1, X 2, side and posterior views, X 2, juvenile shell, paratype USNM 154867d; 13-15, ventral views, X 1, X 2, side, X 2, juvenile pedicle valve, paratype USNM 154867e; 16-21, ventral views, X 1, X 2, side, dorsal, anterior, and posterior views, X 2, paratype shell, USNM 152723m; 22-27, ventral and interior views, X 1, X 2, side and posterior views, X 2, spinose pedicle valve, paratype USNM 154867f; 28-33, ventral and interior views, X 1, X 2, posterior and anterior views, x 2, pedicle valve with attached small shells, para- type USNM 154867g; 34-39, ventral views, X 1, X 2, dorsal, side, posterior, and anterior views, X 2, holotype shell, USNM 152723d; 40-45, ventral and interior views, x 1, X 2, side and anterior views, X 2, pedicle valve, paratype USNM 152723c; 46, interior view, x 3, pedicle valve tilted back to show visceral region, paratype USNM 154867h; 47^8, interior and side views, X 3, small brachial valve, paratype USNM 154867i; 49-52, interior, side, and posterior views, X 3, brachial valve, paratype USNM 154867J; 53-56, interior, visceral, posterior, and side views, X 3, brachial valve, paratype USNM 154867k. [Cathedral Mountain Formation, USNM 726o.] NUMBER 19 1599 PLATE 341.-Echinauris 1600 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 342 Kutorginella Kutorginella sullivanensis (R. E. King): 1-3, Dorsal, ventral, and side views of a siphonate speci- men, X 1, hypotype USNM 149872-1; 4-6, ventral, side, and dorsal views of another siphonate specimen, X 1, hypotype USNM 149872e; 7-9, interior, exterior, and side views of a brachial valve, X 1, hypotype USNM 149872m; 10, 11, posterodorsal and interior views of the preceding brachial valve, x 2, showing cardinal process and marginal rim; 12-14, interior, exterior, and side views of another brachial valve, x 1, hypotype USNM 149872n; 15, 16, posterodorsal and interior views, X 2, of the preceding specimen, showing the marginal rim; 17, 18, interior and side views of another brachial valve, X 1, showing marginal rim and anterior trail, hypotype USNM 149872o; 19, 20, posterodorsal and interior views of the preceding brachial valve, X 2, showing dendritic adductor scars, brachial ridges, and cardinal process; 21, 22, ventral and dorsal views of a specimen preserving its long halteroid spines, X 1, hypotype USNM 149871a; 23, 24, dorsal and ventral views of another specimen preserving its long halteroid spines, X 1, hypo- type USNM 149871b; 25, 26, dorsal and ventral views of a siphonate specimen, X 1, hypotype USNM 149871c; 27-30, ventral, side, interior, and anterior views of a siphonate specimen, X 1, showing ear baffles and inner margin, hypotype USNM 149872h; 31, 32, dorsal and ventral views of a siphonate specimen preserving one of its long halteroid spines, X 1, hypotype USNM 149871d; 33, 34, side and ventral views of a strongly siphonate specimen preserving one of its long halteroid spines, X 1, hypotype USNM 149871c [Road Canyon Formation, USNM 707c] NUMBER 19 1601 PLATE S42.-Kutorginella 4 --^ ®K 1602 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 343 Kutorginella Kutorginella uddeni, new species: 1-4, Anterior, ventral, posterior, and side views of a large pedicle valve, x 1, paratype USNM 149866a. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 70lq.] 5-8, Anterior, side, posterior, and ventral views of a large pedicle valve, X 1, paratype USNM 149857a. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701c] 9-11, Anterior, ventral, and side views of a pedicle valve, x 1, paratype USNM 153906a; 12, Exterior of a brachial valve, X 1, showing the cardinal process, paratype USNM 153906b. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 721h.] 13-17, Side, dorsal, posterior, and ventral views of a complete specimen, x 1, holotype USNM 149855a. [Neal Ranch Formation (upper 15 feet of bed 2 of P. B. King), USNM 701.] Kutorginella umbonata (Muir-Wood and Cooper): 18-22, Side, posterior, dorsal, ventral, and anterior views, x 1, of the holotype USNM 124044b; 23-26, ventral, side, dorsal, and posterior views of a large specimen preserving parts of its halteroid spines, x 1, hypotype USNM 153907a; 27-29, dorsal, side, and ventral views of an immature specimen, showing flattened form, x 1, hypotype USNM 153907c; 30-33, anterior, posterior, dorsal, and side views of a complete speci- men, x 1, showing some of the spines on the brachial valve, paratype USNM 124044c. [Road Canyon Formation, USNM 702c] NUMBER 19 1603 PLATE S4S.-Kutorginella "?V 1604 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 344 Kutorginella Kutorginella umbonata (Muir-Wood and Cooper): 1-3, Ventral, dorsal, and side views of a specimen preserving the long, anterior halteroid spines, X 1, hypotype USNM 149879a; 4-6, side, ventral, and dorsal views of an immature specimen, x 1, showing flattened form, hypotype USNM 153907d; 7, dorsal view of a specimen larger than the preceding but still in the flattened form of immaturity, x 1, hypotype USNM 153907b; 8, ventral view of a pedicle valve, X 1, showing some of the body spines, paratype USNM 124044d; 9, dorsal view of a complete speci- men, X 1, paratype USNM 124044e; 10, anterior view of a large broken specimen, x 1, showing the anterior marginal rim in the brachial valve, hypotype USNM 153907e; 11-13, posterior, interior, and side views of a brachial valve, showing the marginal rim and ear baffles, x 2, para- type USNM 124044h; 14, 15, posterodorsal and dorsal views of the cardinal process of the preceding paratype, x 3; 16, interior of another brachial valve, X 2, showing the spiny marginal rim and ear baffles, paratype USNM 124044m; 17-20, interior, exterior, anterior, and side views of a brachial valve, X 1, showing the marginal rim, ear baffles, and anterior trail, hypotype USNM 153907f; 21, 22, posterodorsal and interior views of the preceding specimen, X 2, showing the strong ear baffles and cardinal process; 23-26, interior, anterior, side and dorsal views, X 1, of another brachial valve, hypotype USNM 153907g; 27, 28, interior and posterodorsal views of the preceding brachial valve, x 2; 29, 30, ventral and side views of a somewhat siphonate, large individual with long anterior halteroid spines, x 1, hypotype USNM 149879b. [Road Canyon Formation (base), USNM 702c] NUMBER 19 1605 PLATE S44.-Kutorginella 1606 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 345 Thamnosia Thamnosia capitanensis (Girty): 1, 2, Interior and exterior of a brachial valve, showing the large, elevated ear baffles, X 1, hypotype USNM 154017a; 3, 4, posterior and interior of the preceding, X 2. [Capitan Formation, USNM 725f.] 5-8, ventral, anterior, side, and posterior views of a pedicle valve, showing the long trail, X 1, hypotype USNM 151478b. [Capitan Formation, USNM 738a.] 9-10, Impression of the brachial valve, and ventral view of the pedicle valve of the same specimen, X 1, showing the long and nasute trail, hypotype USNM 151474b; 11, 12, ventral and anterior views of another nasute pedicle valve, showing also a cincture at the anterior of the visceral region, X 1, hypotype USNM 151474a. [Capitan Formation, USNM 750a.] 13-17, Ventral, side, anterior, posterior, and dorsal views of a complete specimen with nasute trail, X 1, hypotype USNM 151481. [Capitan Formation, AMNH 475.] NUMBER 19 1607 PLATE S45.-Thamnosia 1608 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 346 Thamnosia Thamnosia parvispinosa (Stehli): 1, 2, Interior and side, X 1, of a brachial valve, x 1, hypotype USNM 149890a; 3, 4, interior and posterior views of the preceding brachial valve, X 2, showing high ear baffles and endospines. [Bone Spring Formation, AMNH 625.] 5, 6, Exterior and interior of a deformed brachial valve, X 1, hypotype USNM 154018b. [Bone Spring Formation, USNM 728c] Thamnosia phragmophora, new species: 7-10, Side, dorsal, posterior, and anterior views of a complete specimen, x 1, holotype USNM 151462b; 11-14, partial side, interior, posterior, and tilted interior views of brachial valve, showing high ear baffles, X 1, paratype USNM 151462d; 15, 16, posterior and dorsal views of another complete specimen, X 1, paratype USNM 151462c; 17-19, anterior, posterior, and side views of another complete specimen with long trail, X 1, paratype USNM 151462a. [Word Formation (Appel Ranch Member), USNM 706d.] NUMBER 19 1609 PLATE 346.-Thamnosia j fill 1610 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 347 Thamnosia Thamnosia parvispinosa (Stehli): 1-4, Anterior, posterior, ventral, and side views of a pedicle valve, X I, hypotype USNM 152726b; 6-10, posterior, dorsal, anterior, side, and ventral views of a complete specimen, x 1, hypotype USNM 152726a; 14-18, anterior, dorsal, side, posterior, and ventral views of another complete individual, X 1, hypotype USNM 154018a; 24-26, side, ex- terior, and interior views of a brachial valve, x 1, hypotype USNM 154020; 27, 28, interior and posterior views of the preceding specimen, x 2, showing ear baffles and cardinal process. [Bone Spring Formation, USNM 728c] 5, Fragment of the exterior of a brachial valve, showing the spines, X 1, hypotype USNM 154019d; 19-21, exterior, X 1, and posterior and interior of a brachial valve having a distorted cardinal process, X 2, hypotype USNM 154019c; 22, 23, exterior and side views of a brachial valve having spines, X 1, hypotype USNM 154019b; 29, 30, posterior and interior views of a brachial valve, showing bulbous cardinal process, breviseptum, fine endospines and ear baffles, X 2, hypotype USNM 154019a. [Bone Spring Formation, USNM 728f.] 11-13, Ventral, anterior, and posterior views of a specimen with fine spines, X 1, hypotype USNM 149893. [Bone Spring Formation, USNM 728h.] NUMBER 19 1611 PLATE S47.-Thamnosia 1612 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 348 Thamnosia Thamnosia anterospinosa Cooper and Grant: 1-4, Dorsal, ventral, posterior, and side views of a specimen with both valves and having spines on the brachial valve, X 1, hypotype USNM 155131b; 5-7, side, dorsal, and ventral views of another complete specimen with a thick brush of spines on the trail, X 1, holotype USNM 149852; 15, interior of a fragmentary pedicle valve showing the adductor platform, x 1, hypotype USNM 155131e; 16, 17, exterior and interior of a brachial valve, X 1, hypotype USNM 15513H; 18, 19, interior and posterior views of the preceding specimen, x 2, showing ear baffles, long median ridge, and adductor scars. [Cathedral Mountain Formation, USNM 702un.] 8-11, Posterior, side, ventral, and anterior views of a pedicle valve, X I, hypotype USNM 154021a; 12, interior of a brachial valve, X 1, hypotype USNM 154021b; 13, 14, posterior and interior of the preceding brachial valve, X 2, showing cardinal process, ear baffles, and adductor scars. [Cathedral Mountain Formation, USNM 72lu.] NUMBER 19 1613 PLATE 348,-Thamnosia 1614 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 349 Thamnosia Thamnosia anterospinosa Cooper and Grant: 1-3, Ventral, side, and posterior views, X 1, of a pedicle valve, hypotype USNM 154022a; 4, 5, exterior and interior views of a brachial valve, X 2, showing cardinal process, muscle scars and ear baffles, hypotype USNM 154022b. [Cathedral Mountain Formation, USNM 721 u.] Thamnosia capitanensis (Girty): 6-8, Exterior, side, and interior views of a brachial valve, X 1, hypotype USNM 154017b; 9, exterior of the preceding specimen, X 2, showing cardinal process. [Bell Canyon Formation (Rader Member), USNM 725f.] 10-12, Exterior, interior, and side views of a brachial valve, x 1, hypotype USNM 154023; 13, 14, posterior and interior of the preceding specimen, X 2, showing ear baffles, dendritic adductor scars, and breviseptum. [Bell Canyon Formation (Rader Member), AMNH 410.] 15-17, Side, exterior, and interior views of another brachial valve, X 1, hypotype USNM 154024; 18, posterior view of the preceding specimen, showing the cardinal process, X 2; 19, in- terior of same specimen, X 2, showing breviseptum and relation of ridge to cardinal process. [Bell Canyon Formation (Pinery Member), USNM 733.] NUMBER 19 1615 PLATE 349.-Thamnosia 1616 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 350 Kutorginella Kutorginella sullivanensis (R. E. King): 1-4, Ventral, posterior, dorsal, and side views of a com- plete specimen, X 1, hypotype USNM 149879. [Road Canyon Formation (base), USNM 702c] Kutorginella robusta, new species: 5-7, Interior, exterior, and side views of a brachial valve, X 1, paratype USNM 154025a; 8, 9, interior and posterior of the preceding brachial valve, X 2, showing cardinal process and ear baffles; 13-16, posterior, ventral, side, and dorsal views of a complete specimen, x 1, paratype USNM 149887d; 17-20, side, posterior, dorsal, and ventral views of a complete specimen preserving some of its spines on the brachial valve, X 1, holotype USNM 149887c [Road Canyon Formation, USNM 721o.] 10, 11, Interior and side views of a brachial valve, X 1, paratype USNM 149886a; 12, interior of the preceding specimen, x 2, showing dendritic adductor scars, brachial ridges and ear baffles. [Road Canyon Formation, USNM 719x.] NUMBER 19 1617 PLATE SbO.-Kutorginella 1618 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 351 Thamnosia and Rhamnaria Thamnosia silicica, new species: 1-4, Posterior, anterior, ventral and dorsal views of an imperfect specimen, X 1, paratype USNM 151470. [Hess Formation (Taylor Ranch Member), USNM 702m.] 5-10, Posterior, ventral, side, anterior, ventral (with ventral valve removed), and dorsal views, X 1, holotype USNM 151468b; 11-14, posterior, side, ventral, and anterior views of a large pedicle valve, X 1, paratype USNM 151468a. [Hess Formation (Taylor Ranch Member), USNM 702c] 15-18, Posterior, ventral, side, and anterior views of another pedicle valve, X 1, showing a somewhat nasute anterior, paratype USNM 151469. [Hess Formation (Taylor Ranch Member), USNM 702f.] Rhamnaria vinnula, new species: 19-22, Dorsal, side, ventral, and anterior views of a complete specimen, X I, paratype USNM 152680a; 23-25, posterodorsal, side, and interior views of a brachial valve, x 1, paratype USNM 153904c [Road Canyon Formation, USNM 721J-] 26-28, Posterior, dorsal, and ventral views of an adult, x 1, paratype USNM 152677. [Road Canyon Formation, USNM 719x.] NUMBER 19 1619 PLATE 351.-Thamnosia and Rhamnaria A, WtiUti** "17" 20^ . 21 ^-.r**\ m 24 '""26V 27 '- ^pfei 23 i^r; v 1 25 , .... 3œjj^. - Jk* Z''^^, 1620 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 352 Bathymyonia and Waagenoconcha Bathymyonia nevadensis (Meek): 1, 2, Ventral and dorsal views of a young specimen, X 1, hypo- type USNM 154034a; 3, 4, ventral and dorsal views of an adult, X 1, showing cardinal process and median septum and spines on brachial valve, hypotype USNM 154034b; 5, 6, exterior and interior views of an immature brachial valve, X 1, hypotype USNM 154034c; 7, 8, interior and exterior of a brachial valve smaller than the preceding, x 1, hypotype USNM 154034d; 9-11, ventral, side, and anterior views of a pedicle valve, X 1, hypotype USNM 154034e; 12, ventral view of a small, spiny, pedicle valve, X 1, hypotype USNM 154034f; 13-15, interior, side, and exterior views of a young brachial valve, X 1, hypotype USNM 154034g; 16-19, dorsal, posterior, anterior, and side views of a complete adult pedicle valve, x 1, hypotype USNM 154034h. [Park City Formation (Franson Member, upper), USNM 760.] Waagenoconcha prophetica, new species: 20, Dorsal view of a large brachial valve, X 1, para- type USNM 149668a. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701q.] 21-23, Posterior, anterior, and ventral views of a pedicle valve, X 1, paratype USNM 149669. [Gaptank Formation (E/ddem to-bearing Shale Member of P. B. King), USNM 701v.] NUMBER 19 1621 PLATE 352.-Bathymyonia and Waagenoconcha 1622 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 353 Hercosia, Juresania, and Bathymyonia Hercosia uddeni (Bose): 1, Cross section of a pedicle valve, X 1, showing the median septum and vesicular material in the apical part, hypotype USNM 154036. [Cathedral Mountain Forma- tion, USNM 726y.] Juresania species 1: 2-4, Posterior, side, and ventral views of a pedicle valve, X 1, figured specimen USNM 152736a. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701r.] Juresania species 2: 5-7, Ventral, posterior, and side views of an imperfect pedicle valve, X 1, figured specimen USNM 152739a; 8-10, exterior, side, and interior views of a brachial valve, X 1, figured specimen USNM 152739b; 11, exterior of the preceding specimen, X 2, showing spines and cardinal process. [Neal Ranch Formation (bed 4), USNM 701d.] Bathymyonia nevadensis (Meek): 12, 13, Interior and exterior views of a large brachial valve, X 1, showing muscle scars and roughened posterior margin, hypotype USNM 154034i; 14, frag- ment of the exterior of a pedicle valve, showing spine arrangement, x 2, hypotype USNM 154034J. [Park City Formation (Franson Member, upper), USNM 760.] 15-17, Interior, side, and exterior views of an old brachial valve, x 1, showing thickened cardinal process, hypotype USNM 154035a; 18, posterior of the preceding specimen, x 2, showing the cardinal process. [Park City Formation (Franson Member), USNM 762.] NUMBER 19 1623 PLATE 353.-Hercosia, Juresania, and Bathymyonia r*P*9i¯ ? US m?;;,. r-m^r 1624 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 354 Waagenoconcha Waagenoconcha magnifica, new species: 1-4, Anterior, side, posterior, and ventral views of a young adult, x 1, paratype USNM 149676c; 5, 6, exterior and interior of a young adult brachial valve, X 1, showing matted spines on exterior, paratype USNM 124153a; 7, exterior of the pre- ceding specimen, x 2, showing the profusion of fine spines; 8, 9, interior and exterior of another brachial valve, X 1, paratype USNM 124153c; 10, 11, exterior and interior of a large adult brachial valve, showing median fold on exterior and long median septum and long cardinal process on the interior, x 1, paratype USNM 149676b; 12, posterior view of the pre- ceding specimen, x 2, showing the myophore of the cardinal process; 13, 14, side and interior views of another brachial valve, X 1, paratype USNM 124153b; 15, posterior view of the pre- ceding specimen, x 1, showing the narrow cardinal process. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1625 PLATE 354.-Waagenoconcha 1626 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 355 Waagenoconcha Waagenoconcha platys, new species: 1-5, Dorsal, side, anterior, posterior, and ventral views of the holotype, X 1, USNM 149647. [Road Canyon Formation, USNM 702c] 6-10, Anterior, side, posterior, dorsal, and ventral views of a small adult, x 1, paratype USNM 154027a; 11, interior of the brachial valve, X 1, paratype USNM 154027b. [Road Canyon Forma- tion, USNM 710z.] Waagenoconcha prophetica, new species: 12-16, Dorsal, anterior, side, ventral, and posterior views of a well preserved specimen, x 1, holotype USNM 149670; 17, median portion of the holotype enlarged X 2 to show the anterior differentiation of spine bases. [Graham Formation (Jacksboro Member), Renfro locality 45.] Waagenoconcha magnifica, new species: 18-21, Posterior, ventral, anterior, and side views of a large pedicle valve, X 1, holotype USNM 149676a; 22, interior of a large brachial valve, X 3, showing long median septum, long-shafted cardinal process, and denticulate posterior margin, paratype USNM 149676e; 23, posterior view of the preceding specimen, X 3, showing myophore and denticulated hinge; 24, side view, X 2, of the cardinal process of the preceding specimen. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1627 PLATE 355.-Waagenoconcha 'ii 3 6 f^¯ K'." **fe '*? 1628 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 356 Waagenoconcha Waagenoconcha convexa, new species: 1, 2, Ventral view of an immature specimen, X 3, X 1, showing the long spines, paratype USNM 154028; 6, ventral view of a crushed specimen, x 1, showing the dense mat of very fine spines covering the shell, paratype USNM 154029a. [Road Canyon Formation, USNM 703c] 3-5, Dorsal, X 1, and ventral and dorsal, X 2, views, showing the dense arrangement of very fine spines, paratype USNM 124154. [Road Canyon Formation (base), USNM 703a.] Waagenoconcha magnifica, new species: 7-9, Side, anterior, and posterior views of a small adult, X 1, paratype USNM 149676d; 10, dorsal view of the preceding paratype, x 2, showing dense arrangement of hairlike spines; 11, 12, interior and exterior of a small brachial valve, X 1, paratype USNM 154030b; 13, 14, interior and exterior of the preceding specimen, x 2; 15, 16, interior and ventral views of a small pedicle valve, X 1, paratype USNM 154030a. [Word Forma- tion (Willis Ranch Member) , USNM 706c] NUMBER 19 1629 PLATE 356.-Waagenoconcha IggO SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 357 Waagenoconcha Waagenoconcha convexa, new species: 1-5, Ventral, dorsal, posterior, side, and anterior views, X 1, paratype USNM 149653n; 6-10, ventral, posterior, side, anterior, and dorsal views of a young specimen, X 1, paratype USNM 149653m; 11, 12, dorsal and ventral views, X 1, of another small individual, paratype USNM 149653i; 13, 14, ventral and dorsal views of an immature specimen, X 1, paratype USNM 149653-1; 15-19, dorsal, side, ventral, posterior, and anterior views of an adult, X 1, paratype USNM 149653c; 20-24, posterior, anterior, dorsal, ventral, and side views of another complete specimen, x 1, paratype USNM 149653d; 39-42, dorsal, ventral, posterior, and side views, X 1, holotype USNM 149652; 43, dorsal view of the holotype, X 2. [Road Canyon Formation, USNM 702c] 25-28, Anterior, posterior, ventral, and side views of a pedicle valve, X 1, paratype USNM 154031a; 33-35, exterior, side, and interior views of a brachial valve, X 1, paratype USNM 154031c; 36-38, side, interior, and exterior views, x 1, of another brachial valve, paratype USNM 154031b. [Cathedral Mountain Formation, USNM 721u.] 29, 30, Ventral and dorsal views of a crushed specimen, showing matted spines, X 1, paratype USNM 154032a; 31, 32, ventral and dorsal views of a small specimen, x 1, paratype USNM 154032b. [Road Canyon Formation, USNM 703.] Waagenoconcha sulcata, new species: 44-48, Posterior, anterior, side, ventral, and dorsal views of a complete specimen, X 1, holotype USNM 154033. [Hueco Canyon Formation, USNM 725z.] NUMBER 19 1631 PLATE 357.-Waagenoconcha 1Q32 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 358 Kochiproductus Kochiproductus occidentalis (R. E. King): 1, Ventral view of a fragmentary specimen, X I, cotype YPM 11552 = paratype. [Wolfcamp "Formation" (probably Neal Ranch Formation), R. E. King locality 91a (not given in King's list of localities).] 2, 3, Ventral and dorsal views of a crushed and fragmentary specimen, x 1, lectotype YPM 11548 (specimen bears number 11548 but label and King's legend to his plate 17: figure 20 gives 11528). [Neal Ranch Formation (bed 9, R. E. King), R. E. King locality 93.] Kochiproductus elongatus, new species: 4-6, Dorsal, posterior, and side views, X 1, holotype USNM 152732. [Skinner Ranch Formation (top), USNM 71 Or.] Kochiproductus species 1: 7-9, Posterior, anterior, and side views of a large pedicle valve, X 1, figured specimen USNM 152729. [Skinner Ranch Formation (Decie Ranch Member), USNM 707w.] NUMBER 19 1633 PLATE S58.-Kochiproductus 1634 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 359 Kochiproductus Kochiproductus quadratus, new species: 1, Dorsal view of a large complete specimen, X 1, para- type USNM 153900d; 2-6, dorsal, side, posterior, anterior, and ventral views, X 1, holotype, USNM 124065a; 7, part of exterior of the brachial valve of the holotype, X 2, showing "pro- tective" spines; 8, interior of a very young brachial valve, X 4, showing cardinal process and median septum, paratype USNM 124065i. [Hueco Canyon Formation, USNM 725z.] NUMBER 19 1635 PLATE 359.-Kochiproductus - FlEfe*; K#'-im ;; ;/¯ ?s ?mmm  ? > / 'A 4 ®&-p 7 ^ii'.ff -??? ~ .^Kiw KVV^ ' i i I 10  il ii IfflN 1638 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 361 Kochiproductus Kochiproductus species 3: 1, 2, Interior and exterior of a fragment of the brachial valve, showing the cardinal process, x 1, figured specimen, USNM 152730a. [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] Kochiproductus species 5: 3, Ventral view of a long slender pedicle valve, X 1, figured specimen USNM 152731. [Skinner Ranch Formation (Sullivan Peak Member), USNM 707d.] 4-6, Interior, exterior, and side views of a brachial valve, x 1, figured specimen USNM 153902a; 7, 8, exterior and interior of the posterior part of another brachial valve, X 1, figured specimen USNM 153902b. [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] Kochiproductus aff. K. elongatus, new species: 9, 10, Interior and exterior of a brachial valve having the configuration of K. elongatus (see plate 360: figure 3), X 1, figured specimen USNM 153903a; 11, posterior of a pedicle valve, x 1, figured specimen USNM 153903b. [Cathedral Mountain Formation, USNM 72 lu.] Kochiproductus primitivus, new species: 12, Interior of a brachial valve, X 1, paratype USNM 148951. [Lenox Hills Formation, USNM 704r.] Dorsal view of a partially preserved specimen, X I, paratype USNM 148947a. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 702q.] Dorsal view of another specimen preserving the brachial valve, X 1, holotype USNM 148950. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 701e.] Kochiproductus quadratus, new species: 15, Dorsal view of a complete specimen, showing reticulate and dimpled exterior, x 1, paratype USNM 124065d. [Hueco Canyon Formation, USNM 725z.] Kochiproductus species 6: 16, Posterior view of a pedicle valve, X 1, figured specimen, USNM 152734a; 17, posterior part of a brachial valve with long slender cardinal process, x 1, figured specimen USNM 152734c; 18, 19, fragment of brachial valve, X 1, and X 2, showing the cardinal process, figured specimen USNM 152734b. [Cathedral Mountain Formation, USNM 721u.] NUMBER 19 1639 PLATE 361.-Kochiproductus ?if '"'-" ?i^J'V'JSfil'' ' 'J&' ^ ?**/ Li.'TilM."-,Jtslr V*4-?*5*9 Jr* k m 10 ^-t^U- ?!¯fe."' 1J *', W 1640 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 362 Rhamnaria and Kochiproductus Rhamnaria vinnula, new species: 1-3, Interior, side, and posterodorsal views of a brachial valve, X 1, paratype USNM 153904a; 4-6, interior, posterodorsal and side views of another brachial valve, X 1, paratype USNM 153904b; 7-9, posterodorsal, interior, and side views of somewhat distorted brachial valve, X 1, paratype USNM 153904c; 10-12, exterior, side, and interior views of a large brachial valve, x 1, paratype USNM 153904d; 13-16, dorsal, ventral, side, and anterior views of complete specimen, x 1, paratype USNM 152680b. [Road Canyon Formation, USNM 721j.] 17-20, Dorsal, ventral, side, and anterior views of a complete specimen, X 1, paratype USNM 152676. [Road Canyon Formation, USNM 724a.] 21-24, Anterior, dorsal, side, and ventral views of a complete specimen, x 1, holotype USNM 149359b; 25-28, dorsal, ventral, side, and anterior views of another complete specimen, X 1, paratype USNM 149359c. [Road Canyon Formation, USNM 702c] Kochiproductus quadratus, new species: 29, 30, Interior and posterior views of a brachial valve, X 1, showing cardinal process and septum fused to cardinal process shaft, paratype USNM 153900c; 31, interior view of another adult brachial valve, x 1, showing septum and shaft fused together, paratype USNM 153900b; 32, interior of another fragmentary brachial valve, X 2, showing incomplete fusion of shaft and septum leaving an alveolus, paratype USNM 153900a; 33, dorsal view of a large and nearly complete adult, X 1, paratype USNM 124065b. [Hueco Canyon Formation, USNM 725z.] NUMBER 19 1641 PLATE 362.-Rhamnaria and Kochiproductus 1642 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 363 Dasysaria Dasysaria undulata Cooper and Grant: 1-4, Posterior, side, ventral, and anterior views of a large pedicle valve, X 1, holotype USNM 148914 (= 153880). [Hueco Formation, USNM 720a.] 5, Interior of a large pedicle valve, x 1, showing the lightly impressed muscle scars, hypotype USNM 153879d; 6, interior of the brachial valve belonging to the preceding pedicle valve, X 1; 7, dorsal view of the cardinal process, x 2, of the preceding brachial valve. [Hueco Formation, USNM 719.] Dasysaria welleri (R. H. King): 8-11, Dorsal, posterior, ventral, and side views of a complete specimen, X 1, hypotype USNM 148926a; 12, dorsal view of a large, alate, complete specimen, X 1, hypotype USNM 148926b; 13, 14, side and interior views of the brachial valve, X 1, hypo- type USNM 148927a; 15, dorsal view of the cardinal process of the preceding specimen, X 2. [Putnam Formation, 0.1 mile south of U. S. 80, 2.3 miles west of Putnam, Callahan County, Texas.] NUMBER 19 1643 PLATE S63.-Dasysaria 1644 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 364 Dasysaria Dasysaria undulata Cooper and Grant: 1-3, Ventral, side, and dorsal views of the hypotype, X 1, USNM 148919a; 4, 5, interior of the pedicle and brachial valves of the same hypotype, X 1. [Hueco Formation, USNM 726.] 6, 7, Dorsal and interior views of a brachial valve, x 1, hypotype USNM 148918b; 8, dorsal view of the cardinal process of the preceding specimen, X 2. [Hueco Formation, USNM 728d.] 9-11, Posterior, side, and ventral views of a pedicle valve, X 1, hypotype USNM 153879a; 12-14, posterior, ventral, and side views of another large pedicle valve, X 1, hypotype USNM 153879b. [Hueco Formation, USNM 719.] 15-17, Posterior, ventral, and dorsal views of a large specimen with both valves but minus the anterior part of the trail, x 1, hypotype USNM 148916. [Hueco Formation, USNM 720c] NUMBER 19 1645 PLATE 364.-Dasysaria i i iff /it'--- w :^i;'"i^i:':' ;'-1;' '??iWPBias 1 .; ??;?::' '"'??? '''?'? v\ ?".'' '. \0 mm. 1646 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 365 Dasysaria and Nudauris Dasysaria wolfcampensis (R. E. King): 1-3, Ventral, side, and posterior views of a large pedicle valve, X 1, hypotype USNM 123991a; 4, dorsal view of a complete specimen, x 1, hypotype USNM 123991b; 5-7, side, posterior, and dorsal views of a complete specimen, X 1, hypotype USNM 148921b; 8-10, side, posterior, and ventral views of a large pedicle valve, X 1, hypotype USNM 148921a; 11-13, ventral, side, and posterior views of a ventral valve with strongly wrinkled visceral region, x 1, hypotype USNM 148921c; 14-16, posterior, ventral, and side views of well wrinkled pedicle valve, X 1, hypotype USNM 148921d. [Hueco Canyon Formation, USNM 725z.] Nudauris reticulata, new species: 17, 18, Posterior and interior views of the brachial valve, X 2, showing cardinal process and breviseptum, paratype USNM 124009L [Camp Creek Formation (50 feet below the top), Moore locality 9880.] NUMBER 19 1647 PLATE 365.-Dasysaria and Nudauris 1648 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 366 Xestosia and Nudauris Xestosia schucherti (R. E. King): 1-3, Side, anterior, and ventral views of a ventral valve, X 1, paratype YPM 10764. [Cathedral Mountain Formation, R. E. King, locality 174] Nudauris transversa, new species: 4-8, Side, ventral, anterior, dorsal, and posterior views, X 1, of a complete specimen stripped of its spines, holotype USNM 152746b; 9-12, anterior, side, ven- tral, and posterior views of a pedicle valve, x 1, paratype USNM 152746d; 13-16, posterior, anterior, ventral, and side views of a large pedicle valve, X 1, paratype USNM 152746a; 17-19, anterior, side, and ventral views of a pedicle valve with most of its spines, x 1, paratype USNM 153981a; 20-22, side, posterior and ventral views of another pedicle valve with spines, X 1, paratype USNM 153981c [Hueco Canyon Formation, USNM 725z.] NUMBER 19 1649 PLATE 366.-Xestosia and Nudauris & 1650 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 367 Echinauris, Xestosia, and Nudauris Echinauris cf. E. boulei (Kozlowski): 1-2, Dorsal and side views of a complete specimen X 1, showing dorsal spines, figured specimen USNM 153483a. [Hueco Canyon Formation, USNM 725z.] Xestosia schucherti (R. E. King): 3-6, Posterior, anterior, side, and ventral views of a pedicle valve, x 1, hypotype YPM 10762. [Bone Spring Formation, R. E. King locality 484.] Nudauris tribulosa, new species: 7, Interior of a brachial valve, x 1, paratype USNM 152747e; 8, 9, interior of another brachial valve, X 1, X 2, showing cardinal process and breviseptum, paratype USNM 152747f; 10-13, side, ventral, anterior, and dorsal views of a small adult with some of its spines, X 1, paratype USNM 152747a; 14-17, anterior, dorsal, side, and ventral views of the holotype, x 1, USNM 152747c; 18, view of the holotype nestled among flakes of the alga Eugonophyllum as it was found after decalcification of the block in which it occurred, X ca. 0.5. [Neal Ranch Formation (bed 4 of P. B. King), USNM 727c] NUMBER 19 1651 PLATE 367.-Echinauris, Xestosia, and Nudauris 1652 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 368 Nudauris Nudauris linospina, new species: 1, Ventral view of a small pedicle valve, x 1, paratype USNM 148860a. [Cathedral Mountain Formation, USNM 702-low.] 2-6, Ventral, anterior, posterior, dorsal, and side views of a young specimen, x 1, paratype USNM 148863a; 7-11, side, dorsal, posterior, anterior, and ventral views, x 1, paratype USNM 148863b; 12-14, ventral, posterior, and dorsal views of a young specimen, X 1, paratype USNM 153982a; 15, ventral view, x 1, of an immature specimen, paratype USNM 153982c [Cathedral Mountain Formation, USNM 703b.] 16-19, Posterior, dorsal, ventral, and anterior views of a large, complete adult, X 1, paratype USNM 148856a; 20-24, anterior, side, posterior, ventral, and dorsal views of a young adult, X 1, paratype USNM 148856b; 25-29, posterior, anterior, side, ventral, and dorsal views of the holo- type, x 1, USNM 148856c [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1653 PLATE S68.-Nudauris 1654 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 369 Nudauris Nudauris presplendens, new species: 1-5, Dorsal, posterior, ventral, anterior, and side views, X 1, of the holotype USNM 148887. [Graham Formation (Jacksboro Member), USNM 510.] Nudauris reticulata, new species: 6-8, Posterior, ventral, and side views of a pedicle valve, X 1, paratype YPM 10667. [Neal Ranch Formation, R. E. King locality 92.] 9, Fragmentary interior of the pedicle valve, X 1, showing the muscle scars, paratype USNM 124009J; 10, 11, side and interior views of the brachial valve, X 1, paratype USNM 124009f (for enlarged views, see plate 365: figures 17, 18); 12-16, side, posterior, anterior, ventral, and dorsal views, X 1, holotype, USNM 124009e; 17-19, ventral, posterior, and side views of a large pedicle valve, X 1, paratype USNM 124009a; 20, dorsal view of another complete specimen, X 1, paratype USNM 148905. [Pueblo Formation (Camp Creek Member), Moore locality 9880.] Nudauris linospina, new species: 21, 22, Interior, X 1, and posterior, X 2, views of a brachial valve, showing cardinal process and breviseptum, paratype USNM 148860c; 23, ventral view of an immature pedicle valve, X 1, paratype USNM 148860b. [Cathedral Mountain Formation, USNM 702-low.] Interior of another brachial valve, x 1, paratype USNM I48846d. [Cathedral Mountain Formation USNM 702.] Interior of the pedicle valve, showing thick adductor platform and surrounding diductor scars, X 1, paratype USNM 153983. [Cathedral Mountain Formation, USNM 703a:.] 26-29, Posterior, dorsal, anterior, and ventral views of a damaged specimen, showing part of the interior, X 1, paratype USNM 153982b. [Cathedral Mountain Formation, USNM 703b.] NUMBER 19 1655 PLATE S69.-Nudauris 1656 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 370 Nudauris Nudauris splendens, new species: 1-4, Anterior, posterior, side, and ventral views of a large pedicle valve, x 1, paratype USNM 152745. [Gaptank Formation, (Uddenites-bearing Shale Member), USNM 701e.] 5-9, Posterior, ventral, side, dorsal, and anterior views X 1, of the holotype, USNM 148872a; 10-14, side, ventral, posterior, dorsal, and anterior views of another complete specimen, X 1, paratype USNM 148872b; 15, 16, exterior and interior of a fragmentary brachial valve, X 1, para- type USNM 148872k; 17, interior of the preceding specimen, X 2, showing the cardinal process and brachial ridges; 18, 19, interior of another fragmentary brachial valve, X 1, X 2, showing the cardinal process and brachial ridges, paratype USNM 148872-1; 20, posterior of the preceding specimen, x 2, showing the myophore of the cardinal process; 21, interior of a fragmentary pedicle valve, X 1, showing the muscle scars. [Neal Ranch Formation (upper 15 feet of bed 2 of P. B. King), USNM 701.] NUMBER 19 1657 PLATE 370.-Nudauris 1658 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 371 Nudauris and Xestosia Nudauris convexa, new species: 1-3, Anterior, side, and posterior views of the holotype, X 1, USNM 152742. [Lenox Hills Formation, USNM 705.] Nudauris enigmatica, new species: 4-6, Side, posterior, and anterior views, X 1, paratype, USNM 152750a; 7-9, anterior, posterior, and side views, x 1, holotype, USNM 152750b. [Skinner Ranch Formation (Poplar Tank Member), USNM 708c] Nudauris aff. N. enigmatica, new species: 10, 11, Interior and exterior views of a brachial valve, X 1, figured specimen USNM 153984; 12, 13, same specimen, X 1.5. [Skinner Ranch Formation (Poplar Tank Member), USNM 707ha.] Xestosia cf. X. schucherti (R. E. King): 14, 15, Dorsal and ventral views of a poorly preserved complete specimen, X 1, figured specimen 148867. [Bone Spring Formation, AMNH 591.] NUMBER 19 1659 PLATE 371.-Nudauris and Xestosia 1660 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 372 Nudauris Nudauris diabloensis Stehli: 1-4, Dorsal, posterior, anterior, and interior views of a brachial valve, x 1, hypotype USNM 153985b; 5-8, dorsal, anterior, posterior, interior views of another brachial valve, x 1, hypotype USNM 153985a; 9-12, side, posterior, ventral, and anterior views of a large pedicle valve, X 1, hypotype USNM 152748b; 13-16, posterior, dorsal, anterior, and interior views of a brachial valve, X 1, showing the brachial ridges and cardinal process, hypotype USNM 152748f; 17-20, anterior, posterior, side, and ventral views of a large pedicle valve, X 1, hypotype USNM 152748a. [Bone Spring Formation, USNM 728c] NUMBER 19 1661 PLATE S72.-Nudauris 1662 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 373 Rugatia Rugatia convexa, new species: 1-5, Posterior, anterior, ventral, dorsal, and side views of a pedicle valve preserving some of its long halteroid spines, X 1, holotype USNM 149530d; 6-10, posterior, anterior, dorsal, side, and ventral views of a large specimen with both valves, X 1, paratype USNM 149530e; 11-15, posterior, dorsal, ventral, anterior, and side views of a young adult, x 1, paratype USNM 149530b; 16-19, posterior, ventral, side, and anterior views of a specimen preserving a long body spine, x 1, paratype USNM 149530a. [Road Canyon Formation (base), USNM 702c] NUMBER 19 1663 PLATE S7S.-Rugatia 1664 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 374 Rugatia Rugatia paraindica (McKee): 1, 2, Partial side and side views of a specimen broken to show the breviseptum and cardinal process, X 1, hypotype USNM 123439b; 4, 5, dorsal and interior views of a brachial valve, X 1, hypotype USNM 154004; 9-12, side, posterior, anterior, and dorsal views of a complete specimen with bored shell, X 1, hypotype USNM 123438e; 13, dorsal view of a small adult with some of its halteroid spines, x 1, hypotype USNM 1234439a; 14, 15, interior and side views of a brachial valve interior, x 1, showing brachial ridges and adductor scars, hypotype USNM 123439c; 16, 17, dorsal and ventral views of the posterior of the preceding specimen, X 2, showing the cardinal process and muscle scars; 18, 19, dorsal and ventral views of a complete specimen with long halteroid spines, x 1, hypotype USNM 123439f. [Cathedral Mountain For- mation, USNM 702un.] 3, Interior of an incomplete brachial valve, x 1, showing adductor scars, hypotype USNM 154003. [Cathedral Mountain Formation, USNM 721u.] 6, Interior of a brachial valve, X 1, showing brachial ridges, hypotype USNM 123996a; 7, ventral view of a pedicle valve, X 1, hypotype USNM 123996d; 8, fragment of a pedicle valve, X 1, show- ing adductor platform, hypotype USNM 149515.[Cathedral Mountain Formation, USNM 702.] NUMBER 19 1665 PLATE S74.-Rugatia 19 J** i> h i"J#4A 1666 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 375 Rugatia Rugatia paraindica (McKee) : 1-4, Ventral, side, posterior, and anterior views of a large specimen playing host to Hercosia, x 1, hypotype USNM 154002a, 5-7, ventral, side, and posterior views of a pedicle valve with bifurcated ear spine, x 1, hypotype USNM 154002c [Cathedral Mountain Formation, USNM 726o.] 8, 9, Ventral and dorsal views of a large pedicle valve with unusually long spines and "gastropod" boring, x 1, hypotype USNM 149520 (this specimen was suspended by its spines among branch- ing bryozoans); 10, interior of a large and greatly thickened specimen with both valves in contact but separable, X 1, hypotype USNM 14952H; 11, pedicle valve of the preceding specimen, showing ginglymus and adductor platform, x 1; 12, brachial valve of the preceding specimen, X 1, showing adductor scars and brachial ridges; 13, myophore of the preceding specimen, X 2, showing also a chilidial structure. [Cathedral Mountain Formation, USNM 702un.] NUMBER 19 1667 PLATE S75.-Rugatia '&M?1 S3*? *w* 1668 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 376 Rugatia Rugatia mckeei, new species: 1, 2, Exterior and interior of the brachial valve, X 1, paratype USNM 149534a; 3-7, anterior, side, ventral, dorsal, and posterior views of a complete specimen, X 1, paratype USNM 149535a; 8-12, anterior, ventral, dorsal, side, and posterior views of a com- plete specimen, x 1, holotype USNM 149534b. [Road Canyon Formation, USNM 707c] 13, 14, Interior and dorsal views of a brachial valve, X 1, paratype USNM 154001. [Road Canyon Formation, USNM 703d.] NUMBER 19 1669 PLATE S76.-Rugatia 1670 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 377 Rugatia Rugatia incurvata (R. E. King): 1-5, Ventral, side, posterior, anterior, and dorsal views, X 1, holotype YPM 11583. [Road Canyon Formation, R. E. King locality 46.] 6-10, Dorsal, anterior, posterior, side, and ventral views of a small specimen, x 1, hypotype USNM 152751c; 20-24, dorsal, posterior, side, anterior, and ventral views of an adult with some of its spines, X 1, hypotype USNM 152751a; 44, interior of a brachial valve, X 1, hypotype USNM 152751d; 45, 46, exterior and interior, X 2, of the preceding specimen showing breviseptum and cardinal process. [Road Canyon Formation (base), USNM 702c] 11-14, Ventral, anterior, posterior, and dorsal views of a complete specimen, X 1, hypotype USNM 154006a; 15, 16, interior and posterior views of the brachial valve of the preceding specimen, X 1; 37, 38, interior and exterior views of the brachial valve, X 2, hypotype USNM 154006b; 39, 40, interior of the pedicle valve, X 1, X 2, showing adductor platform, hypotype USNM 154006c 17-19, Interior, X 1, X 2, and exterior, x' 2, of a brachial valve, hypotype USNM 154007. [Road Canyon Formation, USNM 703c] 25, Ventral view of an immature pedicle valve, X 1, hypotype USNM 154005b; 26-30, dorsal, ventral, side, anterior, and posterior views of an adult, x 1, hypotype USNM 154005d; 31, dorsal view of a young specimen with long halteroid spines, x 1, hypotype USNM 154005a; 32-35, posterior, anterior, side, and ventral views of a large and spiny pedicle valve, X 1, hypotype USNM 154005e; 36, ventral view of the preceding specimen, x 2, showing the numerous spines; 41, in- terior of a brachial valve, x 1, hypotype USNM 154005g; 42, 43, interior and exterior of the preceding brachial valve, X 2, showing cardinal process, adductor scars, breviseptum, and endo- spines. [Road Canyon Formation (base), USNM 703a.] NUMBER 19 1671 PLATE S77.-Rugatia ?;?'.:'"" :" jg| | ""; . '? "'?' ^r ^fl ErfaKr - 91 35 36 1672 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 378 Rugatia and Reticulatia Rugatia occidenlalis parvauris, new species: 1-3, Ventral, anterior, and side views of a fine pedicle valve, X I, holotype USNM 153471. [Cathedral Mountain Formation, USNM 702.] 4, 5, Side and interior views of an imperfect brachial valve, X 1, paratype USNM 154008a; 6-8, posterior, interior, and side views of another brachial valve, X 1, paratype USNM 154008b. [Cathedral Mountain Formation, USNM 726y.] Rugatia occidentalis (Newberry): 9-12, Posterior, side, ventral, and dorsal views of an internal mould, x 1, showing deep slit produced by adductor platform, hypotype USNM 154009; 13, latex replica of the brachial valve interior prepared from the preceding, x 1, showing brachial ridges and fine endospines. [Kaibab Formation, USGS 664.] Reticulatia huecoensis (R. E. King): 14-17, Side, anterior, posterior, and dorsal views of the holo- type, x 1, YPM 10554. [Hueco Canyon Formation, R. E. King locality 380.] Reticulatia species 2: 18-20, Posterior, side, and ventral views of a large pedicle valve, X 1, figured specimen 148998. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701 v.] NUMBER 19 1673 PLATE 378.-Rugatia and Reticulatia 1674 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 379 Spinarella Spinarella paulula, new species: 1-3, Ventral, dorsal, and side views of an immature specimen, X 1, paratype USNM 149527g; 4-7, posterior, dorsal, side, and ventral views of a complete speci- men, x 1, paratype USNM 149527b (for a view showing ear spines see plate 380: figure 18); 8-10, ventral, side, and dorsal views of another complete specimen, X 1, paratype USNM 149527c; 11-13 ventral, side and dorsal views of an immature specimen, X 1, paratype USNM 149527d; 14-17, ventral, posterior, dorsal and side views of another complete individual, X 1, paratype USNM 149527h. [Road Canyon Formation (base), USNM 702c] 18-21, Ventral, posterior, anterior, and dorsal views, X 1, holotype USNM 153470a; 22, interior of a fragment of a brachial valve showing the cardinal process and breviseptum, X 1. paratype USNM 153470b; 23, 24, interior and side views of the preceding specimen, X 2, showing the cardinal process; 25, 26, interior and posterior views of a brachial valve, X 1, paratype USNM 153470c; 27, posterior of the preceding specimen, showing the myophore, X 2. [Road Canyon Formation, USNM 719x.] Spinarella perfecta, new species: 28, 29, Ventral and interior views of a pedicle valve, X I, showing muscle field and endospines, paratype USNM 148844h; 30-33, ventral, side, posterior and dorsal views of a complete specimen, x 1, holotype USNM 148844a; 34, 35, posterior and interior views of a brachial valve, X 1, paratype USNM 148844L [Road Canyon Formation (base), USNM 702c] NUMBER 19 1675 PLATE 379,-Spinarella 1676 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 380 Spinarella Spinarella perfecta, new species: 1-4, Side, anterior, posterior, and ventral views of a pedicle valve, X 1, paratype USNM 148844e; 5, 6, right side and posterior views of the preceding speci- men, X 2, showing the row of spines on the ear; 7-10, posterior, ventral, dorsal, and side views of a large complete specimen, X 1, paratype USNM 148844c; 11-13, exterior, interior, and posterior views of the brachial valve, X 1, paratype USNM 148844J; 14-16, interior, posterior, and dorso- posterior views of the preceding specimen, X 2, showing brachial ridges, breviseptum and cardinal process. [Road Canyon Formation (base), USNM 702c] Spinarella paulula, new species: 17, Posterior of the brachial valve interior, X 2, showing cardinal process, paratype USNM 153470d. [Road Canyon Formation, USNM 719x.] 18, Posterior of a pedicle valve showing row of spines on ear, X 2, paratype USNM 149527b (for additional views of this specimen, see plate 379; figures 4-7). [Road Canyon Formation (base), USNM 702c] NUMBER 19 1677 PLATE S80.-Spinarella 1678 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 381 Spinarella Spinarella costellata, new species: 1-4, Posterior, side, ventral and dorsal views of a complete specimen, X 1, holotype USNM 148842a; 5, interior of the pedicle valve of the holotype, X 1, showing granulose interior and muscle field; 6, 7, interior of the brachial valve of the holotype, X 1, X 2, showing brachial ridges and abundant endospines; 8-11, dorsal, ventral, side and pos- terior views of another imperfect individual, x 1, paratype USNM 148842b. [Road Canyon For- mation, USNM 703d.] Spinarella lobata, new species: 12-16, Dorsal ventral, anterior, posterior, and side views of a com- plete individual, x 1, paratype USNM 148843e; 17-21, anterior, posterior, dorsal, ventral, and side views of a strongly lobate specimen, x 1, holotype USNM 148843a; 22, 23, ventral and dorsal views of another complete specimen, x 1, paratype USNM 148843f; 24, interior of the pedicle valve of the preceding paratype, x 1, 25, interior, X 1, of the brachial valve of the preceding paratype, X 1, showing breviseptum; 26, posterior of the brachial valve, X 2, of the preceding specimen showing low cardinal process. [Road Canyon Formation, USNM 707c] 27-31, Dorsal, posterior, ventral, anterior, and side views of a complete, less deeply indented specimen than the preceding ones, X 1, paratype USNM 154010a; 32-36, posterior, ventral, side, anterior, and dorsal views of a complete individual, X 1, paratype USNM 154010b. [Road Canyon Formation, USNM 719x.] NUMBER 19 1679 PLATE S8\.-Spinarella 1680 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 382 Xestosia Xestosia schucherti (R. E. King): 1-5, Dorsal, anterior, posterior, ventral, and side views of a com- plete and well formed specimen, x 1, hypotype USNM 152744a; 6, 7, interior and side views of a brachial valve, X 1, showing fine breviseptum and endospines, hypotype USNM 153998f (see plate 383: figure 12, for enlarged posterior view); 8, 9, interior and side views of another brachial valve, X 1, hypotype USNM 153998c; 10, interior of a fragmentary pedicle valve, X 1, showing muscle scars and ginglymus, hypotype USNM 153998b. [Cathedral Mountain Formation, USNM 721u.] Xestosia obsolescens, new species: 11, Ventral view of an immature specimen with long halteroid spines, X 1, paratype USNM 148861h; 12, 13, interior and posterior of a fragmentary brachial valve, X 1, showing sharp breviseptum, paratype USNM 148861g; 14, 15, side and interior views of a brachial valve, X 1, showing brachial ridges, paratype USNM 148861k; 16, posterior of the preceding specimen, x 2, showing the cardinal process; 17, 18, posterior and dorsal views of an immature individual, X 1, paratype USNM 148861 j; 19, dorsal view, X 1, of a complete specimen, paratype USNM 148861a; 20, 21, interior of the pedicle and brachial valves of the preceding speci- men, x 1, showing brachial ridges, breviseptum, and depressed cardinal process; 22-25, posterior, ventral, side, and dorsal views of another specimen, x 1, holotype USNM 148861b; 26, interior, X 1, of the holotype. [Cathedral Mountain Formation, USNM 702un.] NUMBER 19 1681 PLATE S82.-Xestosia 1682 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 383 Xestosia and Reticulatia Xestosia schucherti (R. E. King): 1-5, Ventral, posterior, side, dorsal, and anterior views of an imperfect specimen with both valves, x 1, paratype YPM 10763a; 6-9, posterior, side, anterior, and ventral views, X 1, lectotype YPM 10763b. [Cathedral Mountain Formation, R. E. King locality 120.] 10, Ventral view of an immature pedicle valve, X 1, hypotype USNM 153998g; 11, posterior of a brachial valve, X 2, hypotype USNM 153998d; 12, posterior of another brachial valve, X 2, showing the cardinal process, hypotype USNM 153998f (for interior view, see plate 382: figures 6, 7); 13, ventral view of a nearly adult pedicle valve, X 1, hypotype USNM 153998c [Cathedral Mountain Formation, USNM 721u.] Reticulatia americana (Dunbar and Condra): 14-16, Interior, side, and dorsal views of a large brachial valve, x 1, hypotype USNM 149002a. [Neal Ranch Formation (top 15 feet of Gray Lime- stone Member of P. B. King), USNM 701.] 17, 18, Side and interior views of another brachial valve, X 1, hypotype USNM 148999a; 19-22, anterior, ventral, side, and posterior views of a pedicle valve, X 1, hypotype USNM 148999b. [Neal Ranch Formation (beds 5-8 of P. B. King), USNM 713h.] NUMBER 19 1683 PLATE 383.- Xestosia and Reticulatia 1684 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 384 Spinifrons Spinifrons quadrata Stehli: 1, Ventral view of an immature pedicle valve, X 1, hypotype USNM 148931; 7, 8, posterior and ventral views of another immature pedicle valve, X 1, hypotype USNM 154014L [Bone Spring Formation, USNM 728c] 2, Ventral view of a young pedicle valve, showing halteroid spines, X 1, hypotype USNM 155035; 9-11, side, interior, and exterior views of a young brachial valve with exterior spines, and solid shaft, X 1, hypotype USNM 153842b; 12, posterior view of the preceding brachial valve, X 2, showing the myophore. [Bone Spring Formation, USNM 728h.] 3-6, Side, dorsal, posterior, and ventral views of a complete specimen, X 1, hypotype USNM 148942. [Bone Spring Formation, AMNH 631.] Spinifrons magna, new species: 13, 14, Exterior and interior of a young brachial valve with partially filled shaft, x 1, paratype USNM 154013e; 15, interior of the preceding specimen, X 2, showing the partially filled shaft of the cardinal process; 16, 17, dorsal and interior views of an adult brachial valve showing a solid-shafted cardinal process and lobate myophore, X 2, para- type USNM 154011c; 18, exterior of a brachial valve, showing the long protective spines, X 1, paratype USNM 154013b; 19, myophore, X 2, of the preceding specimen. [Bone Spring Formation, USNM 728f.] NUMBER 19 1685 PLATE S84.-Spinifrons m ?>> JfK. 1686 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 385 Spinifrons Spinifrons delicatula, new species: 1-4, dorsal, ventral, posterior and side views of an imperfect pedicle valve, x 1, paratype USNM 154015a; 5, interior of the pedicle valve of the preceding specimen, X 1; 6, posterior view of the cardinal process of the preceding brachial valve, X 2; 7, 8, exterior and interior of a fragmentary pedicle valve, showing the muscle scars, X 1, para- type USNM 154015b. [Skinner Ranch Formation (base), USNM 724p.] 9-12, Dorsal, ventral, anterior, and side views of a complete specimen, x 1, holotype USNM 148929. [Skinner Ranch Formation (base) USNM 71 lp.] Spinifrons magna, new species: 13, 14, Ventral views of two immature pedicle valves, X 1, X 2, showing initial rings of attachment, paratype USNM 154016a, b; 15-17, interior, posterodorsal, and exterior views of a young brachial valve, X 1, showing open cardinal process shaft, paratype USNM 154016d; 18, 19, posterodorsal and interior vieiws of the preceding brachial valve X 2, showing immature cardinal process; 20, ventral view of an immature pedicle valve, X 1, paratype USNM 154014-1; 21, 22, exterior and interior of another brachial valve, X 1, paratype USNM 15401 le; 23, interior of an immature brachial valve, x 1, paratype USNM 15401 If; 24, 25, interior and posterodorsal views of the preceding specimen, x 2, showing open-shafted cardinal process and narrow myophore; 26, interior of a brachial valve deformed in growth, X 1, paratype USNM 15401 lg. [Bone Spring Formation, USNM 728f.] NUMBER 19 1687 PLATE S85.-Spinifrons 1688 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 386 Reticulatia, Antiquatonia, Calliprotonia and Echinaria Reticulatia robusta, new species: 1, Very young specimen, X 3, showing the initial attachment ring and early spines, paratype USNM 153840. [Neal Ranch Formation (bed 4 of P. B. King) , USNM 721g.] Antiquatonia inflativentra, new species: 2-5, Anterior, side, ventral, and posterior views of a ped- icle valve, X 1, paratype USNM 148965b; 6-9, posterior, anterior, side, and posterior views of the holotype, X 1, USNM 148965c [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701c] Calliprotonia species: 10-13, Dorsal, side, ventral, and anterior views of a small, rare specimen, X 1, figured specimen USNM 149684. [Neal Ranch Formation (bed 4), USNM 701d.] Echinaria cf. E. moorei (Dunbar and Condra): 14, Interior of a pedicle valve, X 1, showing the long cardinal process, figured specimen USNM 153841; 15, 16, dorsal and side views of an incom- plete specimen, x 1, figured specimen USNM 149689a; 17, ventral view of a pedicle valve, X 1, figured specimen USNM 149689b. [Gaptank Formation USNM 702n.] NUMBER 19 1689 PLATE 386.-Reticulatia, Antiquatonia, Calliprotonia, and Echinaria 1690 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 387 Spinifrons Spinifrons quadrata Stehli: 1, Ventral view of an immature pedicle valve preserving the initial attachment ring, x 2, hypotype USNM 154014a; 2, 3, interior and exterior of an immature brachial valve, X 1, showing open cardinal process, hypotype USNM 154014b; 4, 5, interior and exterior of another pedicle valve slightly larger than the preceding but showing the same features, X 1, hypotype USNM 154014c; 6, 7, exterior and interior of a brachial valve larger than the preceding but with open cardinal process, X 1, hypotype USNM 154014d; 8, exterior of a brachial valve showing spines on the exterior, X 1, hypotype USNM 154014e; 9-12, ventral, side, posterior, and anterior views of a young pedicle valve, X 1, hypotype USNM 154014g; 13-16, posterior, anterior, side, and ventral views of another young pedicle valve, X 1, hypotype USNM 154014J; 17-20, ventral, posterior, side, and anterior views of an adult pedicle valve, X 1, hypotype USNM 1540141; 21-24, posterior, side, anterior, and ventral views of an adult pedicle valve with long, stout spines on the trial, X 1, hypotype USNM 154014k; 25-28, side, posterior, anterior, and ventral1 views of a large pedicle valve with stout halteroid spines on the trail, X 1, hypotype USNM 154014m. [Bone Spring Formation, USNM 728c] NUMBER 19 1691 PLATE 387.-Spinifrons >5X & 1Mb 2-3 4 5 ^'>V< * '.' II 11' m\¯ i > '//rl ? m ?- 12 19 20 ^u mm 15 26 ??::>œ2*v fllli Asaft?®&v 1692 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 388 Spinifrons Spinifrons magna, new species: 1, 2, Posterodorsal and interior views of a fragment of the brachial valve, X 1, preserving a young cardinal process, paratype USNM 154011b; 3-5, interior, exterior, anterointerior views of a brachial valve preserving its endospines on the trail and spines on the exterior, X 1, paratype USNM 154013a; 6-8, interior, side, and exterior of a large brachial valve, X 1, showing the brachial ridges and cardinal process shaft solidly filled in, paratype USNM 154013f; 9, 10, exterior and interior of another brachial valve, X 1, showing external spines and solid shaft of cardinal process, paratype USNM 154013c; 11-13, side, ventral, and anterior views of a pedicle valve, X 1, paratype USNM 148932b. [Bone Spring Formation, USNM 728f.] NUMBER 19 1693 PLATE S88.-Spinifrons J594 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 389 Spinifrons Spinifrons magna, new species: 1-3, Interior, exterior, and posterior views of an immature brachial valve, X 1, showing a juvenile cardinal process, paratype USNM 154011a; 4-7, posterior, side, ventral, and anterior views of a pedicle valve, X 1, showing the large halteroid spines on the trail, paratype USNM 148932c; 8-11, posterior, side, anterior, and ventral views of a large pedicle valve, x 1, paratype USNM 154012a; 12-14, side, posterior and dorsal views of a large complete specimen, x 1, holotype USNM 148932a. [Bone Spring Formation, USNM 728f.] NUMBER 19 1695 PLATE S89.-Spinifrons 1696 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 390 Spinifrons and Antiquatonia Spinifrons quadrata Stehli: 1-4, Side, anterior, posterior, and ventral views of a young adult, X 1, hypotype USNM 153842a. [Bone Spring Formation, USNM 728h.] 5-7, Posterior, ventral, and side views of a young ventral valve, X 1, hypotype USNM 153843. [Bone Spring Formation, USNM 728c] Antiquatonia planumbona Stehli: 8-13, Posterior, anterior, side, ventral, laterally tilted, and dorsal views of a complete specimen, X 1, showing ridge and spine row adjacent to the ear, hypotype USNM 148988a; 14, 15, interior and exterior of a broken brachial valve, X 1, showing brachial ridges and oblique ridge adjacent to the ear, hypotype USNM 148988b; 16, posterior view of the preceding specimen, x 2, showing the myophore of the cardinal process. [Bone Spring Formation, USNM 728f.] 17-21, Posterior, anterior, laterally tilted, side, and ventral views of a pedicle valve, X 1, show- ing the spine ridge adjacent to the ear, hypotype USNM 148987. [Bone Spring Formation, USNM 728c] 22, Immature specimen referred to Antiquantonia planumbona, X 4, showing initial attach- ment ring and early spines, hypotype USNM 153844. [Bone Spring Formation AMNH 629.] NUMBER 19 1697 PLATE 390.-Spinifrons and Antiquatonia m< % T'' Ifol r ?*' J? l \ ri?r * SI '''' i- '. ' ' , " 1W. I . fife-1; ^Si#® 1700 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 392 Reticulatia Reticulatia robusta, new species: 1-4, Side, posterior, dorsal, and ventral views, X 1, holotype USNM 148997; 5, 6, dorsal and posterior views of a complete specimen, X 1, paratype USNM 148996. [Neal Ranch Formation (bed 4), USNM 701d.] Reticulatia species 2: 7-10, Anterior, side, ventral, and posterior views of a large pedicle valve, X 1, figured specimen USNM 149005. [Gaptank Formation (Uddenites-bearing Shale Member of P. B. King), USNM 701p.] NUMBER 19 1701 PLATE 392.-Reticulatia 1702 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 393 Reticulatia Reticulatia species 1: 1-4, Posterior, ventral, anterior, and side views of a large specimen, X 1, figured specimen USNM 148994a; 5-8, posterior, side, ventral and anterior views of a large pedicle valve, x 1, figured specimen USNM 148994b. [Neal Ranch Formation (beds 12-14 of P. B. King), USNM 701c] 9, 10, Side and dorsal views of a specimen with both valves, X 1, figured specimen 149018. [Lenox Hills Formation, USNM 731i.] NUMBER 19 1703 PLATE 39S.-Reticulatia 1 -*1. ,_:-..-~~ ***-Vrt t *" ftp a -?- ... $ 1704 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 394 Peniculauris Peniculauris subcostata (R. E. King) : 1, 2, Exterior of a brachial valve, X 1, X 2, showing fine spines, hypotype USNM 148810. [Cathedral Mountain Formation, USNM 703b.] 3, Interior of a fragmentary pedicle valve, x 1, showing thickened adductor ridge and muscle scars, hypotype USNM 152754c; 4-7, ventral, posterior, side, and anterior views of a large pedicle valve, x 1, hypotype USNM 152754b. [Cathedral Mountain Formation, USNM 724i.] Exterior of a pedicle valve, X 1, showing the brush of spines on the ear, paratype of Peni- culauris mckeei Muir-Wood and Cooper, USNM 123446d. [Cathedral Mountain Formation, USNM 702.] 10, Ventral and dorsal views of an imperfect specimen, x 1, X 2, holotype YPM 11837. [Ca- thedral Mountain Formation, R. E. King locality 123.] 11, Posterior view of the supposed "cardinal area" (= ginglymus), X 2, paratype T10155a; 12, interior of another fragment, showing part of muscle scar and "cardinal area" (= ginglymus), X 2, paratype T10155b. [Cathedral Mountain Formation, R. E. King locality 119.] NUMBER 19 1705 PLATE 394.-Peniculauris 1706 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 395 Peniculauris Peniculauris subcostata (R. E. King) : 1, 2, Posterior and ventral views of a pedicle valve with spine- tufted ears, x 1, hypotype USNM 148791. [Cathedral Mountain Formation, USNM 703b.] 3, 4, Side and ventral views of another pedicle valve, x 1, paratype of P. mckeei USNM 123446a; 5-8, side, posterior, ventral, and dorsal views of the holotype of P. mckeei Muir-Wood and Cooper, X 1, USNM 123445; 9, 10, interior and posterodorsal views of the brachial valve showing the cardinal process, x 1, paratype of P. mckeei USNM 123446d (for pedicle valve interior see plate 396: figure 8, [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1707 PLATE 395.-Peniculauris 1708 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 396 Peniculauris Peniculauris subcostata ( R. E. King): 1, 2, Dorsal and side views, X 1, of a complete specimen, hypotype USNM 123446c (= 152753); 3-5, interior, dorsal, and side views of the preceding speci- men, X 1, showing brachial ridges, thickened breviseptum and cardinal process; 6, myophore of the preceding specimen, X 2. [Cathedral Mountain Formation, USNM 702un.] 7, Exterior of a brachial valve, X 1, showing the fine ornament spines, hypotype USNM 148802a; 8, interior of a pedicle valve, X 1, showing muscle scars, paratype of P. mckeei USNM 123446d (for brachial valve interior of the specimen, see plate 395: figures 9, 10). [Cathedral Mountain Formation, USNM 702.] 9, Interior of a brachial valve, X 1, showing cardinal process, breviseptum extended by thick- ening to the cardinal process, and the large brachial ridges, hypotype USNM 148789; 10, myo- phore, x 2, of the preceding brachial valve. [Cathedral Mountain Formation, USNM 703b.] NUMBER 19 1709 PLATE 396.-Peniculauris 1710 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 397 Peniculauris Peniculauris subcostata (R. E. King): 1-5, Posterior, ventral, anterior, side, and dorsal views of a complete specimen, x 1, hypotype USNM 153993; 6, 7, side and interior views of the brachial valve of the preceding specimen, x 1; 8, myophore of the cardinal process, X 2, of the preceding speci- men. [Cathedral Mountain Formation, USNM 703b.] Peniculauris ivesi (Newberry): 9-12, Side, posterior, dorsal, and ventral views of a worn and im- perfect specimen, x 1, lectotype USNM 5356a; 13, interior of the brachial valve, X 1, paratype USNM 5356b. [Kaibab Formation, Banks of the Colorado River, near the mouth of Diamond Creek, Grand Canyon of the Colorado, Arizona, according to Newberry (1861). The label with the specimens (probably correct) reads: "Mesa west of Little Colorado (Camp 70)."] NUMBER 19 1711 PLATE 397.-Peniculauris /-.; 1712 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 398 Peniculauris Peniculauris subcostata (R. E. King): 1-5, Dorsal, ventral, side, anterior, and posterior views, X 1, showing part of the spine tuft, hypotype USNM 148809. Cathedral Mountain Formation, USNM 703a1.] 6, 7, Posterior and ventral views of a pedicle valve, X 1, retaining part of the spine tufts on the ears, hypotype USNM 153994a; 8, 9, interior and exterior of a large brachial valve, X 1, hypo- type USNM 153994b (note sponge spicules, a possible source of silica, covering part of the ex- terior); 10, posterior view of the preceding specimen, X 2, showing the cardinal process, which is in a juvenile condition. [Cathedral Mountain Formation, USNM 721u.] 11, Interior of a pedicle valve, X 1, showing large adductor platform, hypotype USNM 148785. [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1713 PLATE S98.-Peniculauris i r 4 ,* m ? ,^' fmSt 4' mm ¯\iv J - * ' 1714 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 399 Peniculauris Peniculauris costata, new species: 1, Interior of the brachial valve, X 1, showing cardinal process and brachial ridges, paratype USNM 148829 (for pedicle valve, see plate 400: figures 6-10). [Road Canyon Formation, USNM 703.] 2, 3, Ventral and side views of a fragment of the pedicle valve showing the small ornament spines, x 1, paratype USNM 148831d; 4-6, ventral, side, and dorsal views of a specimen with both valves, X 1, holotype USNM 148831c; 7, interior of the holotype X 1, showing cardinal process and brachial ridges. [Road Canyon Formation, USNM 703d.] 8-10, Posterior, dorsal, and ventral views of a large, worn and imperfect individual, X I, para- type USNM 148832. [Road Canyon Formation, USNM 707c] NUMBER 19 1715 PLATE 399.-Peniculauris tfjf ' 1716 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 400 Peniculauris Peniculauris costata, new species: 1-5, Side, ventral, anterior, posterior, and dorsal views, X 1, of a young individual, paratype USNM 148830. [Road Canyon Formation, USNM 703c] 6-10, Posterior, side, interior, ventral, and anterior views of a large pedicle valve, X 1, para- type USNM 148829 (for dorsal interior, see plate 399: figure 1) . [Road Canyon Formation, USNM 703.1 NUMBER 19 1717 PLATE 400.-Peniculauris 1718 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 401 Peniculauris Peniculauris costata, new species: 1, 2, Ventral and posterior views of a fragmentary pedicle valve, X 1, showing the short body spines, paratype USNM 148831a; 7, cardinal process, X 2, of the bra- chial valve of the holotype USNM 148831c (for interior view of this specimen, see plate 399: figure 7); 8, interior of a fragmentary pedicle valve, x 1, showing adductor platform, paratype USNM 148831b. [Road Canyon Formation, USNM 703d.] 3-6, Ventral, dorsal, posterior, and anterior views of a complete but young specimen, x 1, paratype USNM 148833. [Road Canyon Formation, USNM 707c] Peniculauris imitata, new species: 9, Posterior of a large pedicle valve, showing its ear spines, X 1, paratype USNM 148792a. [Hess Formation (Taylor Ranch Member), USNM 702d.] 10-12, Posterior, side, and ventral views of a large pedicle valve, X 1, holotype USNM 148823b. [Hess Formation (Taylor Ranch Member), USNM 716o.] 13, Interior of the brachial valve, X 1, paratype USNM 148826a. [Hess Formation (Taylor Ranch Member), USNM 722p.] NUMBER 19 1719 PLATE 401.-Peniculauris 1720 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 402 Peniculauris Peniculauris imitata, new species: 1, 2, Interior and exterior of a brachial valve, X 1, paratype USNM 153995b; 3, posterior of the preceding specimen, X 2, showing the myophore; 6-8, pos- terior, ventral, and side views of a large pedicle valve, x 1, paratype USNM 148792b. [Hess Formation (Taylor Ranch Member), USNM 702d.] 4, 5, Side and ventral views of the internal mold of a pedicle valve, showing the muscle scars, X 1, paratype USNM 148798a, 9-12, ventral, anterior, side, and posterior views of a young narrow, pedicle valve, X 1, paratype USNM 148798b. [Hess Formation (Taylor Ranch Member), USNM 702f.] NUMBER 19 1721 PLATE 402.-Peniculauris 1722 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 403 Peniculauris Peniculauris transversa, new species: 1-5, Dorsal, posterior, anterior, side, and ventral views of a young specimen, X 1, paratype USNM 148835e; 6-10, side, dorsal, posterior, anterior, and ventral views, X 1, holotype USNM 148835a; 11, interior of a brachial valve showing cardinal process and brachial ridges, X 1, paratype USNM 148835b; 12, side view of a young adult, X 1, showing the brush of spines on the ear, paratype USNM 148835f (for another view of this specimen, see plate 404: figure 10). [Road Canyon Formation, (base) USNM 702c] NUMBER 19 1723 PLATE 403.-Peniculauris >p* 1724 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 404 Peniculauris Peniculauris transversa, new species: 1-4, Ventral, posterior, side, and dorsal views of a young adult, x 1, paratype USNM 148835d; 5-9, posterior, ventral, anterior, dorsal and side views of a large, much encrusted specimen, x 1, paratype USNM 148835c; 10, ventral view of a specimen, showing the spine brush on the car and short body spines, X 1, paratype USNM 148835f (for an additional view of this specimen, see plate 403: figure 12). [Road Canyon Formation, USNM 702c] NUMBER 19 1725 PLATE 404.- Peniculauris 1726 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 405 Peniculauris Peniculauris transversa, new species: 1-5, Ventral, dorsal, anterior, posterior, and side views of a large pedicle valve, x 1, paratype USNM 148837b; 6, dorsal view of the cardinal process, X 2, paratype USNM 148837e (for interior and exterior, see plate 406: figures 10, 11). [Road Canyon Formation, USNM 721o.] 7-11, Anterior, posterior, ventral, side, and dorsal views of a complete specimen, X 1, showing the short and delicate ornament spines, X 1, paratype USNM 153996. [Road Canyon Formation, USNM 721s.] NUMBER 19 1727 PLATE 405.-Peniculauris ^^^^H K ? L m v flk,, "M I :'-*#**ti^S ^K -  * ? X ^mmSEq^B WSM a ?; v _ "i/ jjgJjj^B . ^^^viuJS " * _-®^iIm iL >d CO 1728 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 406 Peniculauris Peniculauris peniculifera, new species: 1-3, Dorsal, ventral, and side views of the holotype, X 1, USNM 148840a; 4, 5, side and interior views of the brachial valve of the holotype, X 1; 6, myo- phore of the cardinal process of the holotype, X 2; 7, 8, exterior and interior of another brachial valve, x 1, paratype USNM 148840b; 9, ventral view of a young pedicle valve, showing the nu- merous, slender body spines, x 1, paratype USNM 153997. [Road Canyon Formation (base), USNM 703a.] Peniculauris transversa, new species: 10, 11, Exterior and posterior part of a brachial valve, X 1, paratype USNM 148837e (for posterior view see plate 405: figure 6). [Road Canyon Formation (base), USNM 702c] NUMBER 19 1729 PLATE 406.-Peniculauris 1730 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 407 Peniculauris Peniculauris peniculifera, new species: 1-4, Ventral, anterior, posterior, and dorsal views, X 1, of a specimen preserving an enormous spine brush on the ear, paratype USNM 148839a; 5, fabri- cated dorsal view of the preceding specimen showing restoration with spine brush on both ears, X 1. [Road Canyon Formation, USNM 703a.] NUMBER 19 1731 PLATE 407.-Peniculauris 1732 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 408 Anemonaria Anemonaria sublaevis (R. E. King): 1, Exterior of a pedicle valve, X 1, showing halteroid spines and obscure costae, hypotype USNM 153838. [Cathedral Mountain Formation, USNM 703b.] 2, Exterior of a large pedicle valve, x 1, hypotype USNM 153839. [Cathedral Mountain Forma- tion, USNM 702un.] 3-6, Anterior, ventral, posterior, and side views of a pedicle valve, X 1, showing some of the spines and obscure radii, hypotype USNM 153883a (= holotype of A. inflata Cooper and Grant, 1969); 7, 8, dorsal and anterior views of a complete specimen, x 1, hypotype USNM 152771a; 9, 10, ventral and posterior views of large pedicle valve, X 1.5, showing boring, hypotype USNM 153883b (paratype of A. inflata Cooper and Grant); 11, 12, dorsal and interior views of a specimen, X 2, with part of the pedicle valve broken away to show the median septum, brachial ridges and endo- spines, hypotype USNM 153883c; 13, partial side view of a broken pedicle valve, X 2, showing the lateral halteroid spines, hypotype USNM 153883d; 14, interior of part of a pedicle valve, X 2, showing muscles and corrugated ridgelike baffle, hypotype USNM 153883e; 15, interior of another pedicle valve, x 2, showing the muscle scars, hypotype USNM 153883f; 16, interior of an imper- fect brachial valve, x 2, showing the breviseptum and fine endospines, hypotype USNM 153883g; 17, posterior of the preceding specimen showing the cardinal process, x 4; 18, another brachial valve interior, X 2, showing the brachial ridges, hypotype USNM 153883h; 19, posterior of the preceding in full view, x 4, to show the cardinal process; 20, posterior of the same specimen slightly tilted and showing the small zygidium, x 4; 21, interior of a brachial valve with few endospines, X 2, hypotype USNM 153883i; 22, large pedicle valve exterior showing spines, X 2, hypotype USNM 153883J. [Cathedral Mountain Formation, USNM 721u.] 23-25, Side, anterior, and posterior views, X 1, of a specimen preserving some of the spines, hypo- type USNM 152770a; 26, dorsal view of the preceding specimen, x 2, showing brachial valve in place. [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1733 PLATE 408.-Anemonaria 1734 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 409 Liosotella Liosotella costata, new species: 1, 2, Ventral and dorsal views of an immature specimen preserving one of the long halteroid spines, x 1, paratype USNM 153946a; 3-6, ventral, dorsal, anterior, and posterior views of a complete specimen preserving some of its halteroid spines, X 1, paratype USNM 149576a; 7, 8, dorsal and ventral views of a young adult not yet having become costate, X 1, paratype USNM 153946b; 9-13, ventral, posterior, anterior, dorsal, and side views of another young, compressed adult with early costation, X 1, paratype USNM 149576b; 14, ventral view of the preceding specimen, x 2; 16, 17, ventral view of a large adult preserving the bases of some of its spines X 1, X 2, paratype USNM 149576e; 18-22, dorsal, anterior, posterior, side, and ventral views of a large costate adult, x 1, paratype USNM 149576d; 23, ventral view of the preceding specimen, X 2, showing spine arrangement; 30-34, posterior, side, anterior, dorsal, and ventral views of a costate specimen, with some halteroid spines, X 1, paratype USNM 149576f; 35-39, dorsal, side, anterior, ventral, and posterior views, x 1, holotype, USNM 149578; 40, ventral view of the holotype, X 2; 41-45, dorsal, ventral, anterior, posterior, and side views of a strongly costate paratype, x 1, USNM 149576g; 46, dorsal view of an immature specimen without costae, X 1, paratype USNM 153946c; 47, ventral view of a smooth immature specimen with halteroid spines, X 1, paratype USNM 153946d; 48, ventral view of another immature specimen, x 1, paratype USNM 153946e; 49-50, interior and exterior of a brachial valve, X I, paratype USNM 1495761; 51, 52, interior and exterior of the preceding specimen, x 2, showing endospines and brachial ridges; 53, 54, interior and exterior of another brachial valve, x 1, paratype USNM 149576h; 55, 56, interior and exterior of the preceding specimen, x 2, showing endospines and zygidium. [Road Canyon Formation, USNM 707c] 15, Dorsal view of a costate adult, x 1, paratype USNM 153947a; 27-29, ventral, side, and dorsal views of a finely costate specimen, x 1, paratype USNM 153947b. [Road Canyon Formation, USNM 724a.] 24-26, Ventral, side, and dorsal views of a large costate specimen, x 1, paratype USNM 153948. [Road Canyon Formation, USNM 724c] NUMBER 19 1735 PLATE 409.-Liosotella 1736 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 410 Nudauris, Echinauris, and Liosotella Nudauris linospina, new species: 1-4, Dorsal, anterior, side, and ventral views of a complete speci- men, x 1, paratype USNM 153944a; 5-8, ventral, dorsal, side, and anterior views of a specimen with well developed cardinal extremities, x 1, paratype USNM 153944b. [Cathedral Mountain Formation, USNM 726u.] Echinauris bella, new species: 9, 10, Dorsal and ventral views of a specimen preserving some of its spines, X I, paratype USNM 153942a; 11, small specimen preserving its body and halteroid spines, X 1, paratype USNM 153942b; 12, ventral view of another small specimen stripped of most of its spines, x 1, paratype USNM 153942c [Cibolo Formation (Thin-bedded Zone of Udden), USNM 738-1.] 13, Posterior view of a specimen preserving two of its long halteroid spines, X 1, paratype USNM 153943. [Cibolo Formation (Thin-bedded Zone of Udden), USNM 738g.] Liosotella costata, new species: 14, Ventral view of two immature pedicle valves, X 1, paratypes USNM 153945a, b; 15, ventral view, X 2, of paratype USNM 153945a, showing the initial attach- ment ring; 16, ventral view, X 2, of paratype USNM 153945b; 17, 18, ventral and dorsal views of a small adult, x 1, paratype USNM 153945c; 19-22, anterior, ventral, dorsal, and side views of a slightly distorted specimen preserving some of its halteroid spines, X 1, paratype USNM 153945d; 23, interior of a pedicle valve, X 1, showing narrowly thickened adductors track, para- type USNM 153945e; 24-27, posterior, side, dorsal, and anterior views of a strongly costate specimen, X 1, paratype USNM 153945f; 28, ventral view of a broken specimen showing part of the brachial valve with long, slender endospines, X 1, paratype USNM 153945g; 29-32, side, an- terior, dorsal, and posterior views of a strongly costate individual, X 1, paratype USNM 153945h; 33-36, anterior, side, dorsal, and posterior views of a specimen with some halteroid spines, X 1, paratype USNM 1539451; 37-40, posterior, dorsal, anterior, and side views of a complete specimen with some of its halteroid spines, X 1, paratype USNM 153945J; 41, 42, dorsal and ventral views of a young specimen nearly flat and without costae, x 1, paratype USNM 153945k; 43, 44, in- terior of a brachial valve, X 1, X 2, showing brachial ridges and endospines, paratype USNM 153945-1; 45, dorsal view of the preceding specimen, X 2, showing the myophore of the cardinal process and zygidium; 46, interior of another brachial valve, x 1, paratype USNM 153945m; 47, 48, interior and exterior of the preceding specimen, x 2, showing median septum and endo- spines; 49, exterior of another brachial valve, x 2, showing the small cardinal process and zygidium, paratype USNM 153915n. [Cibolo Formation (Thin-bedded Zone of Udden), USNM 738-1.1 NUMBER 19 1737 PLATE 410.- Nudauris, Echinauris and Liosotella r N* ^itiif>f ? fi' Mao: 32 w l/ - -3 .' .'- ?- S3 ' tj ?  w/ i 1814 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 449 Megousia Megousia definita, new species: 1, 2, Side and interior of a brachial valve, X 1, paratype USNM 153975a; 3, 4, interior and exterior of the preceding specimen, x 2, showing breviseptum and cardinal process; 5, posterior of the preceding specimen, showing the myophore of the cardinal process, X 4; 6, ventral view of an immature specimen, X 2, paratype USNM 149952c; 7, 8, ventral view of two immature specimens preserving part or all of the initial attachment ring, X 2, paratypes USNM 149952a, b; 9-13, dorsal, anterior, posterior, side, and ventral views of a complete specimen, x 1, paratype USNM 149953d; 14-18, ventral, dorsal, posterior, side, and anterior views of another complete specimen, x 1, holotype USNM 149953a; 19, dorsal view, X 2, of the holotype; 20-24, dorsal, anterior, ventral, side, and posterior views of a complete specimen, X 1, paratype USNM 149953b; 25, dorsal view, x 2, of the preceding specimen; 26-29, anterior, dorsal, ventral, and side views of a specimen with some of the halteroid spines preserved, X 1, paratype USNM 149953g; 30, side view of the preceding specimen, x 2, showing the ear and spines; 31-35, dorsal, posterior, anterior, interior, and side views of the brachial valve, X 1, paratype USNM 149953h; 36, 37, interior and exterior of the preceding specimen, showing the cardinal process and breviseptum, X 2; 38-42, exterior, posterior, anterior, interior and side views of an- other brachial value, X 1, paratype USNM 149953i; 43-46, posterior, dorsal, side, and interior views, X 2, of the preceding brachial valve with well developed alae, cardinal process, and muscle scars. [Word Formation (Willis Ranch Member) , USNM 706c] NUMBER 19 1815 PLATE 449.-Megousia 1816 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 450 Megousia Megousia auriculata Muir-Wood and Cooper: 1-4, Anterior, posterior, dorsal, and side views, X 1, of a brachial valve, hypotype USNM 149925c; 5-8, posterior, interior, dorsal and side views of the preceding specimen, x 2, showing the long alae, cardinal process and breviseptum; 9-11, posterior, anterior, and dorsal views of another brachial valve, x 1, hypotype USNM 149925d; 12-14, side, interior, and exterior views, X 2, of the preceding brachial valve; 15-18, anterior, ventral, side, and dorsal views, X 1, of a complete specimen, hypotype USNM 149925b; 19, 20, dorsal and side views of the preceding specimen, X 2, showing the large alae; 21-25, side, dorsal, ventral, anterior, and posterior views of a complete and alate specimen, X I, hypotype USNM 149925a; 26, dorsal view of the preceding specimen, x 2, showing alae. [Road Canyon Formation, USNM 703d.] 27, 28, Ventral and interior views of a pedicle valve, X 1, hypotype USNM 153976a; 29, interior, X 2, of the preceding specimen; 30, exterior of a brachial valve with wide wings, X 1, hypotype USNM 153976b; 31, interior of the preceding specimen, 2, showing the widely spread wings; 32, dorsal view of a complete specimen, x 2, showing trails, hypotype USNM 153976c; 33, 34, in- terior and exterior of a brachial valve, x 2, showing cardinal process and septum, hypotype USNM 153976d. [Cathedral Mountain Formation, USNM 721u.] 35-38, Anterior, dorsal, posterior, and ventral views of a complete specimen, x 1, hypotype USNM 149923; 39, dorsal view of the preceding specimen, x 2, showing the numerous trails. [Cathedral Mountain Formation, USNM 703b.] 40-43, Ventral, dorsal, posterior, and ventral views of a small complete specimen with long halteroid spines, x 1, hypotype USNM 149915; 44, dorsal view of the preceding specimen, x 2. [Cathedral Mountain Formation, USNM 702a1.] 45^17, Dorsal, side, and ventral views of a small specimen with large wings, X 1, holotype USNM 124108b (for an enlarged view of the holotype, see plate 452: figure 25); 48, exterior, of a brachial valve with wings, X 2, hypotype USNM 149940n. [Road Canyon Formation, USNM 707c] NUMBER 19 1817 PLATE 450.-Megousia 1818 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 451 Megousia Megousia auriculata Muir-Wood and Cooper: 1, 2, Interior and exterior views of an immature pedicle valve, X 3, showing the large attachment ring, hypotype USNM 149929a; 3, 4, interior and exterior of another immature pedicle valve with attachment ring surrounding a segment of crinoid stem, x 3, hypotype USNM 149929b; 5, 43, ventral and dorsal views of an immature pedicle valve preserving early halteroid spines, x 3, hypotype USNM 149929d; 6, 7, ventral view' of a small pedicle valve, X I, X 2, showing remnant of attachment ring, hypotype USNM.149929e; 8, 9, posterior and dorsal views, of the preceding specimen, X 3; 10, 11, ventral view of a small pedicle valve, x 1, X 2, hypotype USNM 149929f; 12, 13, posterior and dorsal views of the pre- ceding specimen, x 3, showing attachment surface and spines; 14, very small specimen, x 4, showing attachment surface at apex, hypotype USNM 149929h; 15-17, ventral, dorsal, and pos- terior views, X 3, showing posterior attachment surface, hypotype USNM 149929-1; 18-20, ventral, dorsal, and posterior views of an immature specimen, x 3, showing attachment surfaces and spines, hypotype USNM 149929m; 21, 42, ventral and dorsal views of a young specimen, X. 2, showing trails and spines, hypotype USNM 149929g; 22, ventral view of the preceding specimen with numerous spines, X 1; 23-25, ventral, dorsal, and posterior views of an immature specimen, X 3, showing attachment surfaces, hypotype USNM 149929s; 26, ventral view of an immature specimen with attachment ring, X 4, hypotype USNM 149929J; 27, ventral view of a pedicle valve with attachment ring, X 4, hypotype USNM 149929i; 28, ventral view of a young specimen, X 4, hypotype USNM 149929k; 29, immature pedicle valve, X 3, with attachment ring, hypotype USNM 149929n; 30, immature pedicle valve, X 3, hypotype USNM 149929q; 31, immature pedicle valve with attachment ring, x 4, hypotype USNM 149929t; 32, immature pedicle valve with attach- ment spines, X 4, hypotype USNM 149929u; 33, immature pedicle valve, X 3, hypotype USNM 149929o; 34, interior of a pedicle valve, X 3, showing attachment spines, hypotype USNM 149929v; 35, 36, interior and ventral views of a pedicle valve having attachment rings, X 3, hypotype USNM 149929c; 41, ventral view of a pedicle valve with long halteroid spine, X 1, hypotype USNM 149925e; 44-47, dorsal, posterior, ventral, and side views of a complete specimen with alae, X 1, hypotype USNM I49940u; 48, 49, side and dorsal views of the preceding specimen, X 2, showing alae. [Road Canyon Formation, USNM 707c] 37-39, Ventral, dorsal, and posterior views, X 1, of a small specimen with long halteroid spines, hypotype USNM 149936; 40, ventral view of the preceding specimen, X 2, showing halteroid spines and wings. [Road Canyon Formation, USNM 712t.] NUMBER 19 1819 PLATE 451.-Megousia 1820 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 452 Megousia and Yakovlevia Megousia? girtyi ( R. E. King): 1-3, Posterior, ventral, and side views, X 1, of the paratype YPM 11501. [Cathedral Mountain Formation, R. E. King localities 23, 24.] 4, 5, Ventral and posterior views of the holotype, X 1, YPM 11507. [Cathedral Mountain For- mation, R. E. King locality Ax.] Megousia umbonata, new species: 6-10, Ventral, side, anterior, posterior, and dorsal views of a strongly costellate specimen, x 1, paratype USNM 149957; 11, dorsal view, x 2, of the preceding specimen. [Cathedral Mountain Formation, USNM 702.] 12-16, Ventral, anterior, side, dorsal, and posterior views of a complete specimen, X 1, paratype USNM 153977; 17, dorsal view, x 2, of the preceding specimen. [Cathedral Mountain Formation, USNM 702-low.] 18, Dorsal view of a complete specimen, X 2, showing the attachment rings, paratype USNM 153978. [Road Canyon Formation, USNM 726d.] Megousia auriculata Muir-Wood and Cooper: 19-21, Interior, posterior, and exterior views, X 2, showing strongly curved ala, hypotype USNM 149924. [Road Canyon Formation, USNM 703c] 22, Interior of the pedicle valve, X 2, hypotype USNM 149929x; 23-25, posterior, ventral, and dorsal views of an immature specimen with attachment surface, X 4, paratype USNM 124108c; 26, dorsal view of the holotype, X 2, showing long wings (for additional views see plate 450: figures 45-47); 27, 28, exterior and interior of a brachial valve, X 2, hypotype USNM 149940r. [Road Canyon Formation, USNM 707c] Yakovlevia hessorum, new species: 29, Small pedicle valve with broken spines, X 1, paratype USNM 153979a (see plate 474: figure 21); 30, pedicle valve with spine on left side distorted, X 1, paratype USNM 153980d; 31, pedicle valve in which large anterior spines have not yet formed, X 1, paratype USNM 151486k; 32, 33, dorsal and side views of a specimen with both valves, X 1, paratype USNM 151486v; 34, ventral view of a pedicle valve preserving halteroid spines, X 1, paratype USNM 154102. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1821 PLATE 452.-Megousia and Yakovlevia *:? 18 l**iuœw 1822 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 453 Megousia, Grandaurispina, Linoproductus, Antiquatonia, and Kozlowskia Megousia mucronata, new species: 1, Exterior of a young specimen retaining the original attach- ment ring, x 1, paratype USNM 149943a; 2, 3, interior and exterior of the preceding specimen, X 3, showing initial attachment ring and accessory spines; 4, 5, exterior of another immature pedicle valve preserving the attachment ring, x 1, X 2, paratype USNM 149943b; 6, interior of the preceding pedicle valve, showing development of coarse pustules along the ear baffles, X 3. [Word Formation (China Tank Member), USNM 706c] Grandaurispina species 7: 7-9, Ventral, anterior, and side views of a slightly distorted pedicle valve, X 1, figured specimen 155046a; 10, exterior of the brachial valve, X 1, showing pits and spine bases, paratype USNM 155046b; 11, 12, exterior and interior of the cardinal process of the preced- ing brachial valve, X 2, [Cathedral Mountain Formation (lower), USNM 721u.] Megousia cf. M. auriculata Muir-Wood and Cooper: 13-16, Dorsal, side, ventral, and anterior views of a small adult, X 1, figured specimen USNM 153929a; 17-20, posterior, anterior, ventral, and side views of a large adult, X 1, figured specimen USNM 153929b. [Road Canyon Formation, USNM 721z.] 21-24, Side, anterior, posterior, and ventral views of another pedicle valve, X 1, figured speci- men USNM 153930. [Road Canyon Formation, USNM 721j.] Linoproductus angustus R. E. King: 25, 26, Interior and ventral views of an old adult pedicle valve, X 1, showing attachment ring and accessory spines making a strong holdfast, hypotype USNM 140222 (Grant 1963, plate 19: figures 27, 31); 27-29, ventral, side and dorsal views of a young adult, showing posterior marginal spines converging for strengthening the attachment of the shell, X 3, hypotype USNM 140209 (Grant 1963, plate 19: figures 10, 11, 15). [Bone Spring Formation, USNM 728f.] Antiquatonia costella, new species: 30-33, Posterior, side, anterior, and ventral views of a large pedicle valve, x 1, holotype USNM 153931. [Lenox Hills Formation (base), USNM 715b.] Kozlowskia alata, new species: 34, Interior of the brachial valve, X 3, showing small cardinal process, breviseptum, thickened brachial ridges, strong ear baffles continuous with the submarginal ridge, and slight development of endospines, paratype USNM 149799a (for additional views, see plate 312: figures 18-20). [Skinner Ranch Formation (base), USNM 705a.] NUMBER 19 1823 PLATE 453.-Megousia, Grandaurispina, Linoproductus, Antiquatonia, and Kozlowskia 1824 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 454 Compressoproductus Compressoproductus thomasi, new species: 1-4, Ventral, posterior, side, and anterior views, X 1, of a small paratype, USNM 151552e; 5-7, posterior, ventral, and side views of a larger pedicle valve than the preceding and with crisscross wrinkles, X 1, paratype USNM 151552c; 8-10, ventral, posterior, and side views of a large specimen with strongly wrinkled shell, X 1, holotype USNM 151552a; 11, 12, posterior and partial side view of another wrinkled pedicle valve, X 1, paratype USNM 151552h; 13, partial side view of the preceding specimen, x 2, showing the ornamentation in detail. [Cathedral Mountain Formation, USNM 708.] 14-16, Partial side, side, and ventral views of a small specimen attached to Institella and show- ing its mode of existence, x 1, paratype USNM 153954a; 17-19, ventral, posterior, and side views of another pedicle valve, X 1, paratype USNM 153954b; 20-22, left, side, ventral, and right side views of a pedicle valve showing the attachment spines, X 1, paratype USNM 153954c [Cathedral Mountain Formation (Wedin Member), USNM 700x.] NUMBER 19 1825 PLATE 454.-Compressoproductus 1826 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 455 Striatifera and Compressoproductus Striatifera linoproductiformis, new species: 1, 2, Ventral and side views of large wrinkled pedicle valve, X 1, paratype USNM 151538a. [Lenox Hills Formation, USNM 705.] Compressoproductus thomasi, new species: 3, Posterior of a fragmentary pedicle valve, showing narrow beak and attachment spines, x 1, paratype USNM 153955a; 4, 5, interior and exterior of a small brachial valve, x 1, paratype USNM 153955b; 6, 7, exterior and interior of another bra- chial valve, x 1, paratype USNM 153955c (for additional views, see plate 457: figures 1, 2). [Ca- thedral Mountain Formation (Wedin Member), USNM 714w.] 8-10, Anterior, posterior, and ventral views of a small adult, X 1, paratype USNM 153956. [Cathedral Mountain Formation, USNM 721u.] Compressoproductus concentricus, new species: 11-14, Anterior, side, posterior, and ventral views of a pedicle valve, x 1, paratype USNM 151542. [Hess Formation (Taylor Ranch Member), USNM 716o.] 15-18, Anterior, posterior, side, and ventral views of a pedicle valve, X 1, paratype USNM 151575b; 19-22, posterior, anterior, side, and ventral views of a pedicle valve, X 1, holotype USNM 151575a; 23, ventral view of the preceding specimen, x 2, showing the ornament. [Skinner Ranch Formation (Decie Ranch Member), USNM 714t.] Compressoproductus species 4: 24, 25, Interior and exterior of an immature ventral valve, X 4, showing attachment ring, figured specimen, USNM 151579a; 26, interior of the brachial valve of a youthful specimen, X 4, showing the bladelike septum continuous with the cardinal process, figured specimen USNM 151579d; 27, posterior of another pedicle valve, X 4, showing initial attachment ring, figured specimen USNM 151579c; 28, small cluster of pedicle valves with initial attachment spines, X 4, figured specimen, USNM 151579b. [Skinner Ranch Formation (Poplar Tank Member), USNM 707ha.] NUMBER 19 1827 PLATE 455.-Striatifera and Compressoproductus 1828 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 456 Compressoproductus Compressoproductus species 1: 1-3, Anterior, ventral, and side views of a young individual, X 1, figured specimen USNM 153959a; 4, ventral view of an immature pedicle valve, X 1, figured speci- men USNM 153959b; 5-8, anterior, posterior, side, and ventral views of a young pedicle valve, X 1, figured specimen USNM 153959c; 9-13, posterior, anterior, ventral, side, and interior views of an adult pedicle valve, x 1, figured specimen USNM 153959d; 14-16, posterior, ventral, and side views of a pedicle valve, X 1, figured specimen USNM 153959e; 17, 18, interior of the brachial valve, x 1, X 2, figured specimen USNM 153959f; 19, interior of a brachial valve, X 2, figured specimen USNM 153959g; 20, 21, ventral and side views of a pedicle valve preserving the attach- ment spines on one side, X 1, figured specimen USNM 153959h. [Road Canyon Formation, USNM 726d.] Compressoproductus flabellatus, new species: 22-24, Exterior, interior, X 1, and interior, X 2, of a brachial valve, paratype USNM 153960a; 25-29, ventral, interior, posterior, side, and anterior views of a pedicle valve, X 1, paratype USNM 153960b; 30-34, anterior, posterior, ventral, side, and interior views of a young pedicle valve, x 1, paratype USNM 153960c; 35-39, posterior, an- terior, side, ventral, and interior views of another pedicle valve, X 1, paratype USNM 153960d; 40^14, side, interior, anterior, posterior, and ventral views of a paratype, X 1, USNM 153960e; 45, 46, exterior and interior of the same paratype, X 2; 47, 48, interior of the brachial valve, X 1, X 2, paratype USNM 153960f; 49, 50, interior of a pedicle valve, x 1, X 2, showing young speci- mens attached, paratype USNM 153960g. [Cathedral Mountain Formation, USNM 726u.] NUMBER 19 1829 PLATE 456.-Compressoproductus .....'-'*-' 50 1830 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 457 Compressoproductus Compressoproductus thomasi, new species: 1, Side view of a large brachial valve, X 1, paratype USNM 153955b; 2, interior of another brachial valve, X 1, showing the cardinal process, paratype USNM 153955c (for additional figures of these specimens, see plate 455: figures 4-7). [Cathedral Mountain Formation (Wedin Member), USNM 714w.] 3, 4, Side and ventral views of a pedicle valve attached to a fenestellid bryozoan, x 1, paratype USNM 151554a; 5, 6, exterior and side of a brachial valve, x 1, paratype USNM 151554b. [Cathe- dral Mountain Formation (Wedin Member), USNM 714w.] Ventral view of a pedicle valve with attached Institella, x 1, paratype USNM 153954d. [Cathedral Mountain Formation (Wedin Member), USNM 700x.] Interior of a large pedicle valve, X 1, paratype USNM 153962. [Cathedral Mountain Forma- tion, USNM 702.] Compressoproductus compressus (Waagen): 9, 10, Ventral and side views of a small specimen, X 1, hypotype USNM 96597a; 11, 12, side and dorsal views of a. long slender specimen, X 1, hypo- type USNM 96597b; 13, interior of a pedicle valve showing beak region, X 1, hypotype USNM 153965. ["Middle Productus Limestone," Wargal Formation (Kalabagh Member) northeast of Kumaranwali Dhok, Warcha Mandi, Salt Range, Pakistan.] 14, 15, Dorsal and side views of a large individual, X 1, hypotype USNM 153963. ["Lower Productus Limestone", Amb Formation, south of dam site, north of Warcha, Salt Range, Pakistan.] 16, 17, Side and interior of a brachial valve, X 1, showing the cardinal process, hypotype USNM 153964. ["Middle Productus Limestone," Wargal Formation (Kalabagh Member), one-half mile west of Khura, Salt Range, Pakistan.] Compressoproductus rarus, new species: 18, 19, Exterior and interior of the brachial valve, X 1, paratype USNM 153966; 20, 21, interior and side of the preceding specimen, X 2, showing the cardinal process and median septum. [Word Formation (China Tank Member), USNM 733q.] 22, Ventral view of a small pedicle valve, X 2, showing attachment spines, paratype USNM 153967. [Word Formation, USNM 732s.] NUMBER 19 1831 PLATE 457.-Compressoproductus 1832 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 458 Compressoproductus Compressoproductus rarus, new species: 1, 2, Side and interior of a young specimen attached to a bryozoan, x 1, paratype USNM 151566k; 3, interior of the preceding specimen, X 2, showing attachment spines; 4, 5, exterior and interior of a brachial valve, x 1, paratype USNM 151565a; 6, 7, interior and side views of the preceding specimen, X 2, showing the cardinal process and long median septum; 8, interior of another brachial valve, X 2, showing same features as pre- ceding specimen, paratype USNM 151565b; 9-13, side, anterior, ventral, interior, and posterior views of a small pedicle valve, X 1, paratype USNM 151566f; 14, ventral view of the preceding specimen, X 2, showing ornament; 15-19, ventral, anterior, posterior, side, and interior views of a medium sized pedicle valve, x 1, paratype USNM 151566e; 20, posterior view of the interior of the preceding specimen, x 2, showing narrow and thickened posterior plates; 21, ventral view of another small pedicle valve, X 1, paratype USNM 151566h; 22, ventral view of a somewhat larger specimen than the preceding with well preserved ornament, X 1, paratype USNM 151566d; 23, ventral view of a nearly fully grown ventral valve, x 1, paratype USNM 151566g; 24-28, ventral, interior, side, anterior, and posterior views of a pedicle valve, X 1, paratype USNM 151566b; 29- 33, side, ventral, anterior, posterior and interior of a strongly convex pedicle valve, X 1, paratype USNM 151566c; 34-37, ventral, side, interior, and anterior views of a large ventral valve, X 1, holotype USNM 151566a; 38, posterior view of the inside of the preceding pedicle valve tilted to show the posterior plates, x 2; 39, anterior view of the preceding specimen, x 2, showing the fine radial ornament and young Rhamnaria pedicle valve. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1833 PLATE 458.-Compressoproductus : & Jfc ! I : , -- / '4 ' \ys 39 36 1834 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 459 Compressoproductus Compressoproductus species 5: 1-3, interior, ventral, and side views of a pedicle valve, X 1, show- ing apical plates in the interior, figured specimen USNM 151567a; 4, ventral view of a wide and spreading pedicle valve, X 1, figured specimen USNM 151567b; 5-7, exterior, interior, and side of a brachial valve, X 1, figured specimen USNM 151567c; 8, side of the preceding, X 2, showing the greatly thickened cardinal process. [Hess Formation (Taylor Ranch Member), USNM 702d.] Compressoproductus parvus, new species: 9-11, Ventral, side, and interior views of an attenuated pedicle valve, X 1, paratype USNM 151545. [Skinner Ranch Formation (Sullivan Peak Member), USNM 722-1.] 12-15, Dorsal, anterior, posterior, and side views of specimen with both valves, X 1, paratype USNM 151560h; 16-19, anterior, side, posterior, and ventral views of a pedicle valve, X 1, showing some quincunxial wrinkling, paratype USNM 151560c; 20-23, posterior, anterior, ventral, and side views of a pedicle valve, X 1, holotype USNM 151560a; 24, side of the holotype, showing the ornament, x 2; 25-27, posterior, ventral and side views of a wrinkled pedicle valve, X 1, para- type USNM 151560b. [Skinner Ranch Formation (Poplar Tank Member), USNM 708c] 28-31, Posterior, anterior, side, and ventral views of a wrinkled specimen, x 1, paratype USNM 153968. [Skinner Ranch Formation (top), USNH 723-1.] Compressoproductus rarus, new species: 32-34, Interior, side, and ventral views of a small pedicle valve, X 1, showing apical plates, paratype USNM 151564. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1835 PLATE 459.-Compressoproductus 1836 smIithsonian CONTRIBUTIONS TO PALEOBIOLOGY PLATE 460 Compressoproductus Compressoproductus species 6: 1-4, Anterior, ventral, posterior and side views of a pedicle valve, X 1, figured specimen 153969a; 5, ventral view of a small pedicle valve, x 1, figured specimen USNM 153969b; 6, ventral view of an immature pedicle valve, X 1, figured specimen USNM 153969c; 7, 8, interior of two brachial valves, x 1, figured specimens 153969d, c [Road Canyon Formation, USNM 721j.] Compressoproductus curtus, new species: 9, 10, Immature ventral valve with attachment ring, X 1, X 2, paratype USNM 151568a; 11-15, anterior, dorsal, posterior, side, and ventral views of a complete specimen, x 1, holotype USNM 151569; 16-20, interior, ventral, posterior, anterior, and side views of a large pedicle valve, X 1, paratype USNM 151568f; 21, interior of the preceding specimen, x 1.5, showing apical plates and endospines around the muscle area; 22-27, ventral, side, interior, anterior, posterior, and interior tilted views, X 1, showing apical plates and mus- culature, paratype USNM 151568g; 28-32, anterior, side, ventral, posterior, and interior views of a large adult, x 1, paratype USNM 151568e; 33, interior of the preceding specimens X 1.5, show- ing muscle area and endospines; 34, 35, side and interior of the brachial valve, X 2, paratype USNM 151568m; 36, 37, exterior and interior of another brachial valve, X 1, paratype USNM 151568n; 38, 39, interior and side views of the preceding specimen, X 2, showing cardinal process. [Cathedral Mountain Formation, USNM 702b.] NUMBER 19 1837 PLATE 460.-Compressoproductus 1838 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 461 Compressoproductus Compressoproductus flabellatus, new species: 1-5, Ventral, interior, posterior, side, and anterior views of a rotund pedicle valve, X 1, holotype USNM 152788a; 6, 7, interior and exterior of a pedicle valve showing thick endospines, X 1, paratype USNM 152788J; 8-12, ventral, interior, side, posterior, and anterior views of another pedicle valve, x 1, paratype USNM 152788e; 13-17, posterior, anterior, ventral, interior, and side views of a large pedicle valve, X 1, paratype USNM 152788k; 18-20, ventral, side, and interior views of a specimen distorted in growth, X 1, para- type USNM 152788-1; 21, 22, dorsal view of a specimen with both valves in place and with the brachial valve partially occupied by a lyttoniid, x 1, X 2, paratype USNM 152788m; 23, 24, ex- terior and interior of a brachial valve, X 1, paratype USNM 152788s; 25, 26, side and interior views of the preceding specimen, X 2, showing the cardinal process and median septum; 27, 28, exterior and interior of another brachial valve, x 1, paratype USNM 152788t; 29, 30, interior and side views of the preceding specimen, x 2, showing the cardinal process and septum; 31-34, ventral, posterior, side, and anterior views of an immature specimen, x 1, paratype USNM 152788o; 35-37, posterior, interior, and ventral views of a small pedicle valve with attachment spines, X 1, paratype USNM 152788n; 38, cluster of small specimens cemented by their spines, X 1, paratype USNM 152788p; 39-43 interior, posterior, anterior, ventral, and side views of a small rounded pedicle valve, X 1, paratype USNM 152788c; 44-48, posterior, side, ventral, an- terior, and interior views of a pedicle valve, x 1, paratype USNM 152788b; 49, 50, exterior and interior of the preceding specimen, showing attachment spines and endospines anterior to the muscle field, X 2; 51-55, anterior, posterior, interior, side, and ventral views of a wrinkled pedicle valve, X 1, paratype USNM 152788f; 56, ventral view of the preceding valve, X 2, showing the ornamentation; 57-59, interior, exterior, and side views of a small brachial valve, X 1, paratype USNM 152788h; 60, side view of the preceding brachial valve, X 2; 61-65, side, anterior, interior, posterior, and ventral views of a small pedicle valve, X 1, paratype USNM 152788d; 66, interior of the preceding specimen, X 2, showing endospines and rhizoid spines. [Cathedral Mountain Formation, USNM 721u.] NUMBER 19 1839 PLATE 461.-Compressoproductus 1840 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 462 Striatifera and Compressoproductus Striatifera linoproductiformis, new species: 1-5, Side, ventral, anterior, posterior, and interior views, X 1, of a small wrinkled individual, paratype USNM 151535; 6, interior of the pedicle valve of the preceding specimen, x 2, showing endospines; 7, 8, interior and side of the brachial valve of the same specimen, x 2, showing cardinal process and endospines. [Neal Ranch Forma- tion (bed 4), USNM 701d.] Compressoproductus acuminatus, new species: 9-13, Ventral, posterior, side, dorsal, and anterior views of a specimen, X 1, preserving its rhizoid spines, paratype USNH 151546e; 53, ventral view, X 2, of the preceding specimen; 14-18, interior, side, ventral, posterior, and interior views of an- other ventral valve, X 1, paratype USNM 151546h (for enlarged view, see plate 463: figure 11); 19-21, interior, X 1, side and interior of a brachial valve, x 2, showing the cardinal process and median septum, paratype USNM 1515461; 22, interior, X 1, of another brachial valve, paratype USNM I51546J; 23, 24, interior and side views, X 2, of the preceding specimen; 25, interior of a brachial valve, X 1, paratype USNM 151546k; 26, 27, interior and side views of the preceding specimen, x 2, showing the cardinal process; 28-32, interior, ventral, side, anterior, and posterior views, of an attenuated ventral valve with lateral rhizoid spines, X 1, paratype USNM 151546f (for an enlarged view of this specimen see plate 463: figure 9); 33-37, interior, side, ventral, dorsal, and posterior views, X 1, of the holotype USNM 151546a; 43, interior of the preceding pedicle valve, X 2, showing interior pustules; 38, 39, interior and exterior of the brachial valve of the holotype, X 1; 40, 41, interior and side views of the brachial valve of the holotype, X 2; 42, dorsal view, X 2, of the holotype, showing both valves in place; 44-48, dorsal, ventral, interior, posterior, and side views of another, extremely attenuate individual, X 1, paratype USNM 151546b; 49, interior of the brachial valve, X 1, of the preceding specimen; 50, 51, interior and side views, X 2, of the brachial valve of the preceding paratype; 52, dorsal view of the preceding paratype, X 2, showing both valves in place. [Road Canyon Formation, USNM 722v.] NUMBER 19 1841 PLATE 462.-Striatifera and Compressoproductus 1842 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 463 Institella, Megousia, Compressoproductus, and Striatifera Institella leonardensis (R. E. King): 1, 2, Ventral and interior views of a pedicle valve, X 1, hypo- type USNM 153970a; 3, 4, exterior and interior of the brachial valve, X 1, hypotype USNM 153970b. [Cibolo Formation (Spicule Zone of Udden), USNM 738f.] Megousia auriculata Muir-Wood and Cooper: 5, 6, Ventral view of a small pedicle valve with long halteroid spines, X 1, X 2, hypotype USNM 153971a; 7, 8, interior of the brachial valve, X 1, X 2, hypotype USNM 153971b. [Cibolo Formation (Thin-bedded Zone of Udden), USNM 738-1.] Compressoproductus acuminatus, new species: 9-11, Exterior view of three specimens, X 2, paratypes USNM 151546f, c, h (for X 1 views of f and h, see plate 462: figures 16, 28-32). [Road Canyon Formation, USNM 722v.] Compressoproductus species 6: 12, 13, Side and interior of a brachial valve, X 2, figured specimen USNM 153969e (for an additional view, see plate 460: figure 8). [Road Canyon Formation, USNM 721j.] Striatifera linoproductiformis, new species: 14-16, Side, ventral, and dorsal views of a complete specimen, x 1, holotype USNM 153972b; 17, dorsal view, x 2, of the preceding specimen; 18, posterior of the holotype, x 3, showing wide hinge; 19, ornament of the holotype near midvalve, X 3; 20-22, side, dorsal, and ventral views of another complete specimen, X 1, paratype USNM 153972a; 23, posterior of the preceding specimen, x 3, showing the wide hinge; 24, dorsal view of the preceding specimen, x 2; 25, ventral view of a specimen X 2, showing the lateral rhizoid spines and the mode of attachment, cementation by the beak, and anchoring by spines, paratype USNM 153972c [Neal Ranch Formation (bed 4), USNM 721g.] NUMBER 19 1843 PLATE 463.-Institella, Megousia, Compressoproductus, and Striatifera I ?.?'. -"". I 4? ?® , Y-.\ . ^F--  W * 1 ? \ 1 ^b J i Awm ^lUfv"* ' '^tfHPH ' H lUSr TV) , t# ¯-^ ? H ^L V.JH 25 1844 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 464 Compressoproductus and Polymorpharia Compressoproductus pinniformis (Girty): 1, 2, Side and dorsal views of a specimen with both valves, X 1, hypotype USNM 153961a; 3-6, anterior, ventral, posterior, and side views of an adult, X 1, hypotype USNM 151526e; 7-9, ventral, side, and posterior views of a wrinkled specimen, X 1, hypotype USNM 151526c; 10-13, ventral, posterior, side, and anterior views of an average pedicle valve, x 1, hypotype USNM 151526d; 14-17, posterior, anterior, ventral, and side views of a small adult, x 1, hypotype USNM 153961b; 18-20, anterior, ventral, and side views, X 1, of a wrinkled pedicle valve, hypotype USNM 151526b; 21, small slab with specimens of different size, X 1, hypotype USNM 153961c; 22, largest specimen on preceding slab in ventral view, X 2, showing the ornament; 23, an immature pedicle valve, X I, hypotype USNM 151526q. [Capitan Formation, USNM 750.] Compressoproductus flabellatus, new species: 24-26, Ventral, posterior, and side views of an im- perfect specimen, X 1, figured specimen YPM 11634. [Cathedral Mountain Formation, R. E. King locality 120.] Polymorpharia polymorpha new species: 27-29, Side, ventral, and interior views of a rare pedicle valve, X 1, figured specimen USNM 154101. [Word Formation (Willis Ranch Member), USNM 724u.] NUMBER 19 1845 PLATE 464.-Compressoproductus and Polymorpharia 1846 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 465 Striatifera Striatifera linoproductiformis, new species: 1-4, Posterior, partial side, anterior, and ventral views of an attached specimen, x 1, paratype USNM 153973a; 5, posterior view of a pedicle valve, show- ing the rhizoid spines, X 1, paratype USNM 153973d; 6, 7, side and posterior views of a specimen with lateral rhizoid spines, X 1, paratype USNM 153973b; 8, 9, posterior and side views of a specimen with numerous lateral rhizoid spines, x 1, paratype USNM 153973c; 10-12, interior, X 1, and interior and side, X 2, of a brachial valve showing cardinal process, paratype USNM 153973e; 13, 14, interior of a large brachial valve, X 1, X 2, showing cardinal process, endospines, and median septum, paratype USNM 153973f; 15-18, interior, ventral, anterior, and side views of a pedicle valve, X 1, paratype USNM 153973g; 19, interior of the preceding specimen, x 2, show- ing endospines; 20-23, ventral, anterior, side, and dorsal views of a specimen with both valves in contact, x 1, paratype USNM 151536a; 24-27, ventral, dorsal, anterior, and side views of a strongly wrinkled specimen, x 1, paratype USNM 151536b; 28-31, anterior, ventral, side, and dorsal views of a complete specimen, x 1, paratype USNM 151536h; 32, side view of the preceding specimen, X 2, showing the ornament and lateral spines. [Neal Ranch Formation (bed 4), USNM 701d.] NUMBER 19 1847 PLATE 465.-Striatifera 1848 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 466 Siphonosia Siphonosia alleni, new species: 1, 2, Ventral and anterior views of a pedicle valve, X 1, showing the early stage of tube development, paratype USNM 152789d; 3, 4, interior and side views of the preceding specimen, X 1.5; 5, ventral view of the preceding specimen, X 2, showing ornament; 6-9, side, posterior, and ventral views of another pedicle valve with early development of tube, X 1, X 1.5, paratype USNM 152789o; 10, ventral view of the preceding specimen, X 1; 11, ventral view, x 1, of a young adult in which the tube has not yet started to form, x 1, para- type USNM 152789e; 12, 13, exterior and interior views, X 2, of the preceding specimen; 14, 15, ventral view of - young specimen, X 1, X 2, paratype USNM 152789p; 16-19, ventral, side, an- terior, and posterior views of a pedicle valve with well developed tube, X 1.5, holotype USNM 152789a; 20-23, anterior, ventral, interior, and side views of the holotype, X 3, showing tube, anchor spines, and anterior rim; 24, ventral view of the holotype, X 1; 25, ventral view of a small paratype with strong ornament, x 1, USNM 152789q; 26, posterior view of a pedicle valve, showing the rhizoid spines, X 2, paratype USNM 152789r; 27, 28, exterior and interior of the brachial valve, X 1, paratype USNM 152789t; 29, exterior of the preceding specimen, X 3, showing ornament; 30, interior of the preceding specimen, X 4, showing elongate brachial ridges, median ridge, and cardinal process; 31, 32, exterior, X 2, and interior, X 4, of another brachial valve, paratype USNM 152789u. [Cathedral Mountain Formation, USNM 721u.] NUMBER 19 1849 PLATE 466,-Siphonosia 1850 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 467 Siphonosia, Megousia, and Undellaria Siphonosia alleni, new species: 1-3, Ventral, interior, and anterior views of a pedicle valve with well formed tube, X 1, paratype USNM 152789s; 4-8, posterior, side, ventral, interior, and anterior views, X 2, of the preceding paratype. [Cathedral Mountain Formation, USNM 721u.] Megousia auriculata Muir-Wood and Cooper: 9, Dorsal view of an immature specimen attached to a crinoid stem, x 1, hypotype USNM 154026; 10, 11, posterior and dorsal views of the preceding specimen, X 3; 12, 13, posterior and partial side views of the preceding specimen, X 5, showing mode of attachment. [Road Canyon Formation, USNM 707c] Undellaria magnifica, new species: 14-17, Ventral, anterior, posterior, and side views, X 1, of the pedicle valve, holotype USNM 152783b; 18-21, posterior, anterior, side, and ventral views of another pedicle valve, larger than the preceding, x 1, paratype USNM 152783a; 22, interior of the preceding pedicle valve, X 1, tilted to show the muscle scars; 23, 24, exterior 1.5 of a brachial valve, X 1, X 1.5, paratype USNM 152783c; 25, interior of the preceding brachial valve, X 2, showing small size of cardinalia; 26, 27, posterior and interior views of the preceding brachial valve, X 3, showing short breviseptum, adductor platforms, and cardinal process; 28, 29, in- terior and posterior views of a fragmentary brachial valve, X 3, showing the cardinal process, adductor platforms, and breviseptum, paratype USNM 152783d. [Bone Spring Formation, USNM 728c] NUMBER 19 1851 PLATE 467.-Siphonosia, Megousia, and Undellaria 1* 1 ?*^r ?®3! 'mjtm j ?PI j HkhHHm 1852 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 468 Horridonia, Echinauris, Institella, Glyptosteges, Siphonosia, and Nudauris Horridonia texana R. E. King: 1, 2, Exterior and interior of a young pedicle valve, X I, hypo- type USNM 153915a; 3, 4, exterior and interior of a young brachial valve, X 1, hypotype USNM 153915b. [Road Canyon Formation, USNM 703c] Echinauris lateralis Muir-Wood and Cooper: 5-9, Side, posterior, dorsal, anterior, and ventral views of an unusually large specimen, X 1, hypotype USNM 153916. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 737w.] Institella leonardensis (R. E. King): 10, Ventral view of an unusually large and strongly frilled pedicle valve, X 1, hypotype USNM 153917. [Cathedral Mountain Formation, USNM 721u.] Glyptosteges sulcatus, new species: 11-15, Ventral, anterior, posterior, side, and interior views of the pedicle valve, x 1, paratype USNM 153918a; 16-18, interior, posterior, and ventral views, X 2, of the preceding specimen; 19, exterior of the brachial valve, X 1, para- type USNM 153918b; 20-22, posterodorsal, interior, and exterior views of the preceding brachial valve, X 2, showing concentric ornament and cardinal process. [Cathedral Mountain Formation, USNM 72lu.] Siphonosia alleni, new species: 23, 24, Interior and exterior of the brachial valve, X 1, paratype USNM 153919; 25, 26, exterior and interior of the preceding brachial valve, X 3, showing median ridge, small cardinal process and wrinkled exterior; 27, 28, ventral and posterior views of the cardinal process of the preceding specimen, X 4. [Cathedral Mountain Formation, USNM 721u.] Nudauris whitei, new species: 29-33, Side, dorsal, posterior, anterior, and ventral views of a complete specimen, x 1, holotype USNM 153920a. [Cibolo Formation (Transition Zone of Udden), USNM 738d.] NUMBER 19 1853 PLATE 468.-Horridonia, Echinauris, Institella, Glyptosteges, Siphonosia, and Nudauris 1854 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 469 Yakovlevia Yakovlevia immatura, new species: 1-4, Dorsal, side, ventral, and anterior views of the holo- type, x 1, USNM 151504a; 5-8, ventral, dorsal, anterior, and side views of another complete specimen, X 1, paratype USNM 151504b; 10, interior of the brachial valve, X 1, paratype USNM 151504g; 9, 11, pedicle valve exterior and interior, X 1, showing ginglymus and muscle scars, paratype USNM 151504d. [Road Canyon Formation, USNM 703d.] Yakovlevia multistriata (Meek): 12-14, Anterior, posterior, and side views, X 1, holotype USNM 646. [Long Valley, northwestern White Pine County, Nevada.] Yakovlevia costellata, new species: 15-18, Dorsal, anterior, posterior, and side views of the holo- type, x 1, USNM 151502a; 19, interior of the pedicle valve, X 1, showing muscle scars and adductor platform, paratype USNM 151502d; 20-22, exterior, interior, and interior tilted of a brachial valve, x 1, paratype USNM 151502c; 23, 24, interior and posterior views of the preceding specimen, X 2, showing brachial ridges and endospines; 25, cardinal process of the preceding specimen, x 4; 26, 27, interior of the pedicle valve, x 1, X 2, showing muscle scars, paratype USNM 151502b. [Cherry Canyon Formation (Getaway Member), USNM 728.] NUMBER 19 1855 PLATE 469,-Yakovlevia 1856 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 470 Yakovlevia Yakovlevia indentata, new species: 1-3, Interior, anterior, and ventral views of a pedicle valve, X 1, paratype USNM 151513c; 4-7, posterior, anterior, side, and dorsal views of a complete specimen, x 1, holotype USNM 151513e; 8-10, interior, anterior, and exterior views, of a brachial valve, x 1, paratype USNM 151513f; 11, 12, posterior and interior views of the pre- ceding specimen, x 2, showing cardinal process, brachial ridges, breviseptum, and adductor scars; 13, cardinal process, X 4, of the preceding brachial valve; 23-25, exterior, interior, and anterior views of another brachial valve, x 1, paratype USNM 151513d; 26, 27, posterior and interior views, X 2, of the preceding brachial valve. [Word Formation (Appel Ranch Member), USNM 7151.] 14, 15, Anterior and ventral views of a pedicle valve, X 1, paratype USNM 154038. [Word Formation (Appel Ranch Member), USNM 7221.] 16-18, Ventral, anterior and interior views of another pedicle valve, X 1, paratype USNM 154039a (for an enlarged view of the interior of this specimen see plate 471: figure 24). [Word Formation (Appel Ranch Member), USNM 719z.] 19-22, Anterior, dorsal, side, and posterior views of a complete specimen, x 1, paratype USNM 154040a; 28, interior of a brachial valve, x 1, paratype USNM 154040b. [Word Forma- tion (Appel Ranch Member), USNM 727j.] NUMBER 19 1857 PLATE 470,-Yakovlevia 1858 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 471 Yakovlevia Yakovlevia intermedia, new species: 1-3, Dorsal, side, and anterior views of a complete specimen, X 1, holotype USNM 151501a; 4-6, anterior, ventral, and side views of a pedicle valve, X 1, paratype USNM 151501b; 7-9, side, dorsal, and anterior views of a complete specimen, X 1, para- type USNM 151501e; 10-12, side, ventral, and anterior views of a pedicle valve, X 1, paratype USNM 151501c; 13, 14, interior view of the preceding specimen, x 1, X 2, showing adductor platform and muscle scars; 15, 16, ventral and side views of a young specimen, X 1, paratype USNM 151501g; 17, interior of an imperfect brachial valve, X 1, paratype USNM 151501h. [Word Formation (China Tank Member), USNM 706c] Yakovlevia indentata, new species: 18-20, Dorsal, anterior, and interior views of a brachial valve, X 1, paratype USNM 154039b; 21, 22, posterior and interior views of the preceding speci- men, x 2, showing brachial ridges, breviseptum, and cardinal process; 23, cardinal process, x 4, of the preceding brachial valve; 24, interior of the pedicle valve, X 2, paratype USNM 154039a (for additional views of this specimen, see plate 470: figures 16-18). [Word Formation (Appel Ranch Member), USNM 719z.] NUMBER 19 1859 PLATE 47\.-Yakovlevia 1860 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 472 Yakovlevia Yakovlevia sulcata, new species: 1, 2, Dorsal and ventral views, X 1, of a young specimen, X 1, paratype USNM 151491h; 3, 4, dorsal and ventral views of another young specimen, X 1, para- type USNM 15149H; 5, 6, ventral and dorsal views of a nongeniculated specimen, X 1, paratype USNM 151491J; 7-10, side, dorsal, anterior, and posterior views of the holotype USNM 151491g; 11-13, ventral, posterior, and anterior views of a specimen preserving the anterior halteroid spines, X 1, paratype USNM 151490a; 14-17, ventral, dorsal, anterior, and side views of a com- plete specimen, x 1, paratype USNM 151491e; 18, ventral view, X 1, showing anterior halteroid spines, paratype USNM 151491o; 19-21, side, ventral, and anterior views of another specimen with its halteroid spines, X 1, paratype USNM 151490b; 22, fragmentary pedicle valve, X 1, showing muscle scars and adductor platform, paratype USNM 151491k; 23, 24, ventral and interior views of another pedicle valve, X 1, showing the muscle scars and adductor platform, paratype USNM 151491-1; 25, interior of a pedicle valve, X 2, showing muscle area and pitted ginglymus, paratype USNM 151491m; 26, 27, posterior and interior views of a brachial valve, X 2, showing brachial ridges, paratype USNM 151491n. [Road Canyon Formation, USNM 707c] 28-30, Ventral, dorsal, and anterior views of a complete specimen, X 1, paratype USNM 154041a; 31, interior of a pedicle valve, x 1, showing a greatly thickened adductor platform, paratype USNM 154041b; 33, 34, exterior and interior of a brachial valve, X 1, paratype USNM 154041d; 35, 36, posterior and interior views of the preceding specimen, X 2, showing brachial ridges; 37, interior of another pedicle valve, X 1, paratype USNM 154041e; 38, 39, posterior and interior views of the preceding specimen, X 2, showing brachial ridges and endospines. [Road Canyon Formation, USNM 722g.] 32, Interior of a pedicle valve, X 2, showing greatly thickened muscle region and adductor platform, paratype USNM 154042. [Road Canyon Formation, USNM 726d.] NUMBER 19 1861 PLATE 472.-Yakovlewia 1862 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 473 Yakovlevia Yakovlevia hessorum, new species: 1, Interior of the pedicle valve, X 1.5, showing muscle field with individual scars, paratype USNM 124051c; 2, ventral view of a young specimen, not yet geniculated, x 1, paratype USNM 151486t; 3, ventral view of a pedicle valve preserving two of its long halteroid spines, X 1, paratype USNM 151485a; 4, interior of another pedicle valve, X 1.5, showing muscle scars, paratype USNM 154037a (for additional views of this specimen see plate 474: figures 7, 8); 5-7, anterior, interior, and exterior views of a brachial valve, X 1, para- type USNM 124051e (for X 2 view, see plate 434: figure 8); 8, exterior of another brachial valve, X 1, paratype USNM 151485b; 9-10, interior and exterior views of the brachial valve, X 1, paratype USNM 153980b; 11, interior of the preceding specimen, X 2, showing brachial ridges and adductor scars; 12, cardinal process of the preceding specimen, x 3; 13, 14, interior of another brachial valve, X 1, X 2, showing strong breviseptum, paratype USNM 153980g; 15, posterior view of the preceding specimen, x 2, showing the cardinal process; 16, posterior of the brachial valve, X 2, showing anterior trails, paratype USNM 154037b; 17, interior of a pedicle valve, X 1.5, showing a pathological muscle area, the diductors of the left side (observer's left) having been aborted, paratype USNM 153979h. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1863 PLATE 473.-Yakovlevia 1864 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 474 Yakovlevia Yakovlevia hessorum, new species: 1, 2, Ventral and side views of a pedicle valve with its halteroid spines preserved, x 1, holotype USNM 153980h; 3, ventral view of a pedicle valve pre- serving an additional pair of halteroid spines, x 1, paratype USNM 153980e; 4, ventral view of an immature pedicle valve preserving some of its early marginal spines, thus resembling a chonetid, X 1. paratype USNM 151486u; 5, 6, exterior and interior of an immature, non- geniculated pedicle valve, X 1, paratype USNM 153979d; 7, 8, interior and exterior of a pedicle valve with part of its halteroid spines preserved, x 1, paratype USNM 154037a (for an enlarged view of the interior see plate 473: figure 4); 9, ventral view of another immature pedicle valve, X 1, showing marginal spines, paratype USNM 151486n (for enlarged view see plate 434: figure 7); 10, 11, exterior and interior of a small brachial valve, X 1, paratype USNM 153979e; 12-14, interior, side, and ventral views of a pedicle valve having remnants of its four halteroid spines, X 1, paratype USNM 153980a; 15, ventral view of a pedicle valve, X 1, having three anterior halteroid spines, paratype USNM 153980J; 16, another pedicle valve with three anterior halteroid spines, X 1, paratype USNM 153980f; 17, 18, ventral and interior views of a young pedicle valve not yet geniculated, x 1, paratype USNM 153979c; 19, 20, interior and exterior of a young brachial valve, x I, paratype USNM 153979g; 21, interior view of a young pedicle valve just be- ginning to geniculate and having just formed its anterior halteroid spines, x 1, paratype USNM 153979a (see plate 452: figure 29); 22, side view of a pedicle valve, showing two of its halteroid spines, X 1, paratype USNM 153980c; 23, ventral view of a young pedicle valve, not yet genicu- lated, X 1, paratype USNM 153979b; 24, ventral view of a pedicle valve having all but one of its halteroid spines and showing the bases of small adventitious spines just posterior to the place of geniculation, x 1, paratype USNM 124051b. [Word Formation (Willis Ranch Member), USNM 706c] NUMBER 19 1865 PLATE 474.-Yakovlevia 1866 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 475 Spyridiophora, Paucispinifera, Limbella, Striatifera, and Orthotichia Spyridiophora reticulata (R. E. King): 1-5, Anterior, dorsal, side, posterior, and ventral views of a specimen preserving its rhizoid spines of attachment, x 1, hypotype USNM 153921. [Skinner Ranch Formation (Sullivan Peak Member), USNM 733j.] Paucispinifera magnispina, new species: 6, Interior of the pedicle valve, X 2, showing the strong ear baffles and the thick adductor platform, paratype USNM 149563c [Word Formation (China Tank Member), USNM 706c] Limbella limbata, new species: 7-9, Ventral, side, and interior views of a pedicle valve, X 1, showing the rhizoid spines and anterior frill, paratype USNM 153922a; 10, interior of a brachial valve, X 1, paratype USNM 153922b. [Skinner Ranch Formation (Sullivan Peak Member), USNM 733j.] Striatifera linoproductiformis, new species: 11, 12, Dorsal and exterior views, X 1, of a large specimen, showing part of the brachial valve in place, x 1, paratype USNM 153923a; 13, in- terior of an obese brachial valve, X 1, showing thickened median septum and cardinal process, paratype USNM 153923b. [Neal Ranch Formation (bed 4 of P. B. King), USNM 727c] Paucispinifera auriculata Muir-Wood and Cooper: 14, Interior of a Cyclacantharia with an immature specimen of Paucispinifera attached within and taking advantage of the shelter afforded by the dead richthofeniid, X 2, hypotype USNM 153924; 15, side view of the preceding specimen, X 3, showing attachment by clasping spines. [Word Formation (Willis Ranch Mem- ber), USNM 706c] Orthotichia newelli, new species (see volume 5): 16-20, Anterior, side, dorsal, posterior, and ventral views of a complete specimen, x 1, paratype USNM 153925. [Cibolo Formation (Breccia Zone of Udden), USNM 738r.] Paucispinifera sulcata, new species: 21, 22, Dorsal view of the cardinal process, X 3, showing well developed zygidium, paratypes USNM 153926a, b. [Road Canyon Formation (base), USNM 702c] NUMBER 19 1867 PLATE 475.-Spyridiophora, Paucispinifera, Limbella, Striatifera, and Orthotichia 1868 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 476 Echinauris, Sestropoma, Paucispinifera, and Rugoclostus Echinauris lappacea, new species: 1-4, Ventral, side, posterior, and anterior views, X 1, of the paratype USNM 154520a; 5-8, anterior, posterior, ventral, and side views of another pedicle valve, X 1, paratype USNM 154520b; 9-12, ventral, side, posterior, and anterior views of another pedicle valve, x 1, paratype USNM 154520c; 13, 14, exterior and interior views of a brachial valve preserving its spines, X 2, paratype USNM 154520d; 15, 16, exterior and interior views of a large brachial valve, showing the brachial ridges and muscle scars, X 2, paratype USNM 154520e; 17, 18, exterior and interior of another brachial valve, X 2, showing the cardinal process and muscle scars, paratype USNM 154520f. [Road Canyon Formation, USNM 732j.] Sestropoma cribriferum Cooper and Grant: 19-21, Apertural (brachial), side, and anterior views of a large pedicle valve with the brachial valve in place, X 1, hypotype USNM 154583a; 22, apertural view of the same specimen with the brachial valve removed, x 1; 23, interior of the brachial valve of the preceding specimen, x 2, showing the bilobed cardinal process; 24, side view of a small pedicle valve, showing the stout attachment spines, x 1, hypotype USNM 154583b; 25, apertural view of a small specimen, showing coscinidium not yet completely united, X 1, hypotype USNM 154583c; 26, apertural view of another young specimen with the coscinidium not yet started on the posterior side, X 1, hypotype USNM 154583d. [Bell Canyon Formation (Rader Member), USNM 740j.] Paucispinifera rara, new species: 27-31, Anterior, dorsal, side, posterior, and ventral views, X 1, holotype, USNM 155119. [Bell Canyon Formation (Pinery Member), USNM 725h.] Rugoclostus semistriatus (Meek): 32-35, Posterior, ventral, side, and anterior views, X 1, of the holotype USNM 652. [Pennsylvanian (probably Manning Canyon Shale), Timpanogos Canyon, Southeast of Salt Lake, Utah.] NUMBER 19 1869 PLATE 476.-Echinauris, Sestropoma, Paucispinifera, and Rugoclostus 1870 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 477 Chonetinetes Chonetinetes angustisulcatus, new species: 1, Dorsal view of two specimens, X 1, paratype (top) and holotype USNM 151815c, a; 2-6, dorsal, anterior, posterior, side, and ventral views, X 3, of the paratype USNM 151815c; 7-11, dorsal, side, ventral, posterior, and anterior views, X 3, of the holotype USNM 151815a; 12, 13, interior and posterior views, X 3, X 4, showing thick median septum and slender anderidia, paratype USNM 151815i; 14, 15, interior and posterior views, X 3, X 4, of another brachial valve, showing lesser internal thickening than the preceding, paratype USNM 151815h. [Road Canyon Formation, USNM 721j.] 16, Dorsal views of two complete specimens, X 1, paratypes 153676a, b; 17-21, posterior, an- terior, side, dorsal, and ventral views of paratype 153676a, showing fine radial ornament, X 3; 22-26, ventral, side, anterior, posterior, and dorsal views, x 3, of paratype USNM 153676b; 27, interior of the pedicle valve, x 3, paratype USNM 153676c; 28, interior of the brachial valve, X 3, paratype USNM 153676d. [Road Canyon Formation, USNM 726d.] Chonetinetes reversus Cooper and Grant: 29, Dorsal view of two complete individuals, X 1, para- type and holotype USNM 153193d, a; 30-33, ventral, posterior, side, and anterior views, X 2.5, holotype USNM 153193a; 34, dorsal view of the holotype X 4; 35-38, anterior, posterior, ventral, and side views of another individual, x 3, paratype USNM 153193c; 39, dorsal view of the preceding paratype, x 4.5; 40, 41, interior and posterior views of a brachial valve, X 3, showing short median septum and deep alveolus in cardinal process, paratype USNM 153193b; 42, 43, interior and posterior views of another brachial valve, X 3, paratype USNM 153193-1; 44, ex- terior of the preceding paratype, X 2; 45, 46, two views of the interior of a pedicle valve, X 2, showing the median septum and pseudodeltidium, paratype USNM 153193k; 47, interior of the preceding paratype, X 3, showing the pseudodeltidium; 48, interior of another pedicle valve with well preserved spine, X 2, paratype USNM 153193L [Road Canyon Formation, USNM 710h.] Chonetinetes varians, new species: 49-53, Ventral, anterior, posterior, dorsal, and side views of a complete specimen with fine radial ornament, x 2, holotype USNM 153677a (for an additional view of the holotype, see plate 502: figure 63); 54-58, side, ventral, anterior, posterior and dorsal views, X 2, paratype USNM 153677b; 59, dorsal views of the two preceding specimens, X 1; (lower is holotype); 60, dorsal view of a thick specimen, x 2, paratype USNM 153678a; 61-65, dorsal, posterior, anterior, ventral, and side views of a small paratype, X 3, USNM 153678b. [Bell Canyon Formation (Hegler Member), USNM 732a.] 66-70, Dorsal, posterior, ventral, anterior, and side views, X 2, paratype USNM 151817c; 71-75, dorsal, side, ventral, anterior, and posterior views, X 2, paratype USNM 151817a; 76, para- types USNM 151817a, c, e, and f, respectively, showing, x 1, dorsal view (upper left and right), pedicle valve interior (lower left), and brachial valve interior (lower right). [Bell Canyon Forma- tion (Hegler Member), USNM 731.] 77, Interior of the brachial valve, showing the short septum and pit in the cardinal process, X 4, paratype USNM 153679. [Bell Canyon Formation (Hegler Member), AMNH 635.] NUMBER 19 1871 PLATE 477.-Chonetinetes 1872 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 478 Chonetinetes, Chonetinella, and Sulcataria Chonetinetes varians, new species: 1, Dorsal view of four specimens, X 1, paratypes (from upper left) 153680c, a, b, and d; 2-6, ventral, posterior, side, anterior, and dorsal views, X 2, para- type USNM 153680a; 7, interior of the pedicle valve, X 2, paratype USNM 153680c; 8-12, ventral, side, dorsal, anterior, and posterior views, X 2, paratype USNM 153680b. [Bell Canyon Forma- tion (Rader Member), USNM 725f.] Chonetinella biplicata (R. E. King): 13-15, Ventral, side, and dorsal views, X 2, holotype YPM 10824. [Bone Spring Formation, R. E. King locality 476.] 16-20, ventral, posterior, anterior, side, and dorsal views of a nearly complete individual, X 1, hypotype USNM 151868a; 21, 22, ventral and dorsal views of the preceding specimen, X 2, showing details of the ornament and the median fold; 23-27, dorsal, ventral, side, an- terior, and posterior views of another complete individual, X 1, hypotype USNM 153681a; 28, 29, dorsal views of the preceding hypotype, X 2, X 3, showing details of the ornament, cardinal process, and chilidium; 30, ventral view of four small specimens, Xl, hypotypes (from upper left) USNM 153681b-e; 31, 32, interior and posterior views, X 3, of a brachial valve, hypotype USNM 153681f; 33, interior of another brachial valve, x 3, showing the thick median septum and spinose inner slope, hypotype USNM 153681g; 34, interior of a pedicle valve, X 1, hypotype USNM 15368H; 35, hinge region of the preceding hypotype, X 2; 36, interior of another brachial valve, X 2, hypotype USNM 153681h; 37, 38, posterior and interior views of the preceding hypotype, x 3, showing thickened anterior slope; 39, interior of a pedicle valve, X 2, showing median septum, hypotype USNM 153681d. [Bone Spring Formation, USNM 728c] 40-43, Side, dorsal, posterior, and ventral views of a complete specimen, X 1, hypotype USNM 151853b; 44, dorsal view of the preceding specimen, x 2; 45, interior of a small brachial valve, X 4, hypotype USNM 151852. [Skinner Ranch Formation (base), USNM 705a.] 46, Dorsal view of a complete specimen, x 2, hypotype USNM 151856. [Skinner Ranch Formation (base), USNM 720c] Chonetinella spinolirata (R. E. King): 47-51, Posterior, ventral, anterior, dorsal, and side views, X 4, holotype YPM 10825. [Neal Ranch Formation, R. E. King locality 91a.] Chonetinella victoriana (Girty): 52-56, Side, posterior, anterior, dorsal, and ventral views, X 3, of YPM 10829, holotype of synonym C. spinoliratus diabloensis R. E. King [Bone Spring Forma- tion, R. E. King locality 479.] Sulcataria latisulcata, new species: 57-61, Dorsal, posterior, anterior, side, and ventral views, X 1, holotype USNM 152082a; 62-66, dorsal, anterior, posterior, ventral, and side views of the holotype, X 2; 67, 68, posterior and interior views of the brachial valve, X 3, showing the cardinal process, anderidia, median septum, and visceral region, paratype USNM 152082b. [Neal Ranch Formation (top 15 feet of P. B. King's bed 2), USNM 701.] NUMBER 19 1873 PLATE 478.-Chonetinetes, Chonetinella, and Sulcataria 1874 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 479 Chonetinella and Leurosina Chonetinella costellata, new species: 1, 2, Exterior and interior, X 1, holotype USNM 151876f; 3-6, anterior, ventral, side, and posterior views of the holotype, X 2, showing the fine radial ornament; 7, interior of the holotype, X 2, showing short median septum; 8-11, posterior, side, anterior, and ventral views of another pedicle valve, X 2, paratype USNM 151876g; 12, dorsal view, x 1, paratypes (from the top) USNM 151876e, b, a; 13, ventral, exterior, X 1, paratype USNM 151876a; 14, ventral view, X 1, paratype USNM 151876b; 15, 16, exterior and interior of a brachial valve, x 1, holotype USNM 151876f; 17, exterior of the holotype brachial valve, X 2; 18, 19, interior and interior view tilted of the holotype brachial valve, X 2, showing short septum and delicate anderidia; 20, posterior of the holotype brachial valve, X 3, showing cardinal process and chilidium; 21, 22, posterior and interior views of another brachial valve with thickened interior details, X 2, paratype USNM 151876h; 23, exterior, X 2, of the pre- ceding specimen. [Neal Ranch Formation (top 15 feet of P. B. King's bed 2), USNM 701.] Chonetinella magna, new species: 24-26, Ventral, side, and anterior views of a pedicle valve, X 1, holotype USNM 151884d; 27-30, ventral, side, posterior, and anterior views of another pedicle valve, x 1, paratype USNM 151884b; 31-33, posterior, interior, and ventral views of a pedicle valve, X 1, paratype USNM 151884j; 34, 35, interior tilted and interior views of a pedicle valve, X 1, showing subdued median septum and papillose inner flanks, paratype USNM 151884e; 36, 37, interior and exterior of a brachial valve, X 1, paratype USNM 151884h; 38, interior of the preceding paratype, X 2, showing median septum, anderidia, and endospinose anterior slope; 39, posterior of the preceding specimen, X 3, showing the cardinal process; 40, 41, interior views of another brachial valve, x 1, paratype USNM 151884c; 42, interior of the preceding paratype, x 2, showing cardinalia and anderidia; 43, posterior view of the pre- ceding specimen, X 3; 44, 45, exterior and interior of a fragmentary brachial valve, X 2, showing cardinal process and anderidia, paratype USNM 151884k. [Bone Spring Formation, USNM 725c] Chonetinella parva, new species: 46, Ventral, posterior, side, anterior, and dorsal views, X 1, paratypes (top) USNM 151872b and (bottom) 151872a; 47-50, dorsal, ventral, side, and anterior views, X 2, paratype USNM 151872b; 51-55, posterior, ventral, anterior, side, and dorsal views, X 2, paratype USNM 151872a. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 701q.] 56, Dorsal view, X I, holotype USNM 151870b (upper) and paratype USNM 151870a (lower); 57-61, anterior, posterior, dorsal, ventral, and side views, X 2, holotype USNM 151870b; 62, dorsal view of the holotype, X 3; 63-67, side, posterior, anterior, dorsal, and ventral views, X 2, paratype USNM 151870a. [Gaptank Formation (Uddenites-bearing Shale Member), USNM 701c] Leurosina lata, new species: 68-72, Posterior, anterior, side, dorsal, and ventral views of a complete specimen, x 1, paratype USNM 153682a; 73, 74, interior and exterior of a pedicle valve, X 1, paratype USNM 153682b; 75, interior of the preceding specimen, X 2; 76, 77, in- terior and exterior of a brachial valve, X 1, paratype USNM 151682c; 78, interior of the preceding specimen, x 2, showing cardinalia. [Road Canyon Formation, USNM 732j.] NUMBER 19 1875 PLATE 479.-Chonetinella and Leurosina  1876 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 480 Chonetinella and Sulcataria Chonetinella victoriana (Girty): 1, 2, Ventral and dorsal views of four immature specimens, X 1, hypotypes (from top) USNM 153683a-d; 3-7, ventral, posterior, side, anterior, and dorsal views of a complete adult, x 1, hypotype USNM 151863d; 8-11, anterior, ventral, dorsal, and side views of the preceding hypotype, X 2; 12-16, posterior, ventral, side, dorsal, and anterior views, X 1, hypotype USNM 151863c; 17-20, ventral, side, dorsal, and anterior views of the preceding specimen, X 2; 21-25, dorsal, posterior, side, anterior, and ventral views, X 1, hypotype USNM 151863b; 26-29, ventral, side, anterior, and dorsal views of a small hypotype, X 2, USNM 151863g; 30, interior of a pedicle valve, x 2, hypotype USNM 153683e; 31, exterior of a brachial valve, x 1, hypotype USNM 153683f (for additional views of this species see plate 500: figures 13-19). [Bone Spring Formation, USNM 728f.] Sulcataria latisulcata, new species: 32, 33, Interior and exterior of a pedicle valve interior, X 1, paratype USNM 152084a; 34, 35, interior and exterior of the preceding paratype, X 2. [Neal Ranch Formation, USNM 701d.] Chonetinella species 2: 36, Ventral view of two pedicle valves, x 1, figured specimens USNM 152790a,b. [Neal Ranch Formation (top 15 feet of P. B. King's bed 2) , USNM 701.] Sulcataria rostrata (Dunbar and Condra): 37, 38, Ventral and dorsal views, x 1, of two hypo- types, USNM 153684a, b; 39, dorsal view of hypotype 153684a, enlarged, x 4, to show pits on exterior; 40-43, ventral, side, posterior, and anterior views of another complete specimen, X 1, hypotype USNM 153684c; 44, exterior of a complete but somewhat crushed individual, X 1.5, showing interareas, hypotype USNM 153684d; 45, exterior of a pedicle valve, x 1, hypotype USNM 153684e; 46, 47, interior and tilted views of the preceding, x 1, showing the thick median callosity bearing the adductor scars; 48, interior of another pedicle valve, showing the muscle scars and papillose lateral margins, X 2, hypotype USNM 153684f; 49, 50, interior of a brachial valve, X 1, X 4, showing cardinalia, strong median septum, and anderidia, hypotype USNM 153684g; 51, exterior of a brachial valve, X 2, showing minute pits, hypotype USNM 153684h; 52, 53, interior and laterally tilted views of another brachial valve, X 2, showing cardinalia and anderidia, hypotype USNM 153684i; 54, posterior of the preceding hypotype, X 3, showing cardinal process; 55, dorsal view of a complete specimen, x 4, showing cardinal process, pseudodeltidium, and chilidium, hypotype USNM 153684b. [Graham Formation (Wayland Member), USNM 510a.] Sulcataria compacta, new species: 56, Posterior, ventral, side, anterior, and dorsal views of the holotype, ca. X 1, USNM 152080a; 57-61, ventral, posterior, anterior, dorsal and side views of the holotype, x 2; 62, interior of the brachial valve, X 3, paratype USNM 152080d. [Neal Ranch Formation (top 15 feet of P. B. King's bed 2), USNM 701.] NUMBER 19 1877 PLATE 480.-Chonetinella and Sulcataria 1878 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 481 Dyoros (Dyoros) Dyoros (Dyoros) attenuatus, new species: 1-3, Posterior, ventral, and side views of a pedicle valve, X 1, paratype USNM 151989; 4, interior of the preceding paratype, X 2, showing short median septum. [Bell Canyon Formation (Hegler Member), AMNH 635.] 5-9, Ventral, posterior, anterior, dorsal, and side views, X 1, of the strongly alate holotype, USNM 151990; 10, same, x 2. [Bell Canyon Formation, USNM 731.] Dyoros (Dyoros) angulatus, new species: 11, 12, Ventral and dorsal views of a complete speci- men, x 1, holotype USNM 153685a; 13-17, anterior, posterior, dorsal, ventral, and side views of the preceding specimen, X 2; 18-21, dorsal, side, anterior, and posterior views of another individual, X 2, paratype USNM 153685b. [Road Canyon Formation, USNM 710z.] 22, 23, Ventral and dorsal views of a complete specimen, X 1, paratype USNM 153686a; 24-28, ventral, dorsal, side, anterior, and posterior views, X 2, of the preceding paratype; 29-32, ventral, posterior, side, and anterior views of another specimen, x 2, paratype USNM 153686b. [Road Canyon Formation, USNM 724a.] 33, 34, Dorsal and ventral views of a complete, mucronate specimen, X 1, paratype USNM 151969a; 35, dorsal view of the preceding paratype, x 2; 36, dorsal view of another paratype, X 2, USNM 151969b; 38, interior of a brachial valve, X 1, paratype USNM 153688; 39, interior of the preceding specimen, x 2, showing the anderidia; 40, posterior of the preceding speci- men, X 3, showing the cardinal process. [Road Canyon Formation, USNM 707c] 37, Interior of a pedicle valve, X 2, paratype USNM 153687a; 41, interior of another brachial valve, X 1, paratype USNM 153687b; 42, 43, interior and laterally tilted views of the preceding paratype, X 2, showing anderidia and median septum; 44, posterior of the preceding specimen, X 3, showing the cardinal process. [Road Canyon Formation, USNM 721 j.] Dyoros (Dyoros) consanguineus (Girty): 45-49, Ventral, posterior, anterior, dorsal, and side views of a complete but small individual, X 1, hypotype USNM 151946J; 50-54, anterior, dorsal, side, posterior, and ventral views of another small complete specimen, X 1, hypotype USNM 151946s; 69, dorsal exterior of the preceding specimen, x 2, showing the smooth shell and median fold; 55-57, anterior, ventral, and interior views of a large pedicle valve, X 1, hypotype USNM 151946o; 58, four small pedicle valves in ventral view, X 1, hypotypes USNM 151946-1, k, m, n; 59, 60, interior of another pedicle valve, X 1, X 2, hypotype USNM 151946r; 61, interior of a pedicle valve having mucronate ears, X 1, hypotype USNM 151946q; 62, interior of a pedicle valve, X 1, hypotype USNM 151946p; 63, interior of a brachial valve, X 1, hypotype USNM 151946y; 64, posterior of the preceding specimen, X 3, showing the cardinal process; 65, 66, in- terior of another brachial valve, x 1, X 2, showing the cardinalia, hypotype USNM 151946u; 67, 68, interior of another brachial valve, X 1, X 4, showing endospines on distal end of median septum, well developed anderidia, and endospines on the anterior slope, hypotype USNM 151946x. [Bone Spring Formation, USNM 728L] NUMBER 19 1879 PLATE 481.-Dyoros (Dyoros) 42 ®œ$b ?--u*-!. & -*s Wk,--'***^ 57 ' Off '* ?a*^ 1880 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 482 Dyoros (Dyoros) Dyoros (Dyoros) consanguineus (Girty): 1-5, Anterior, ventral, dorsal, posterior, and side views of a complete specimen, X 1, hypotype USNM 153689. [Bone Spring Formation, USNM 728c] Dyoros (Dyoros) convexus, new species: 6, Ventral view of five immature specimens, X 1, para- types (from top and left) USNM 151950k, j, i, h, g; 7-11, ventral, side, dorsal, anterior, and posterior views of a small adult, x 1, paratype USNM 151950c; 12-16, ventral, dorsal, posterior, anterior, and side views of a large adult, X 1, paratype USNM 151950o; 17-21, dorsal, side, ven- tral, posterior, and anterior views of an adult, X 1, holotype USNM 151950a; 22, beak region of the preceding specimen, x 4, showing the cardinal process and chilidium; 23, interior of a young brachial valve, X 2, showing cardinalia, paratype USNM 153690a; 24, posterior of the preceding specimen, x 3; 25, median region of the preceding specimen, x 4, showing anderidia and cardinal process; 26, 27, partial side and side views of another brachial valve, showing endospinose median septum and anderidia, x 2, paratype USNM 153690b; 28, 29, partial side and interior views of a brachial valve showing cardinalia, anderidia, and median septum, x 2, paratype USNM 153690c; 30, posterior view of the preceding, x 3, showing cardinal process and chilidium; 31, interior of the pedicle valve, X 1.5, showing median septum, paratype USNM 151950-1. [Cherry Canyon Formation (Getaway Member), USNM 728.] 32, Interior of an old adult, showing excessive development of endospines, x 2, paratype USNM 153691. [Cherry Canyon Formation (Getaway Member), AMNH 519.] Dyoros (Dyoros) magnus Stehli: 33-37, Interior, ventral, side, posterior, and anterior views of a pedicle valve, x 1, hypotype USNM 153692. [Bone Spring Formation, AMNH 631.] 38-42, Dorsal, anterior, posterior, ventral, and side views of a complete but imperfect speci- men, X 1, hypotype USNM 151939. [Bone Spring Formation, AMNH 628.] 43, 44, Exterior and interior, X 1, of an incomplete brachial valve, hypotype USNM 153693; 45, interior of the preceding hypotype, x 2, showing median septum, endospines and anderidia. [Bone Spring Formation, USNM 725c] Dyoros (Dyoros) cf. D. (Dyoros) magnus Stehli: 46-50, Posterior, ventral, side, anterior, and dorsal views of a large, stout, thick-shelled specimen, x 1, figured specimen USNM 151943. [Cibolo Formation (Breccia Zone of Udden), AMNH 703.] NUMBER 19 1881 PLATE 482.-Dyoros (Dyoros) 1882 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 483 Dyoros (Dyoros) Dyoros (Dyoros) extensiformis, new species: 1-5, Ventral, posterior, anterior, side, and dorsal views, X 1, paratype USNM 151971a; 6-10, anterior, dorsal, posterior, side, and ventral views of a specimen smaller than the preceding, x 1, paratype USNM 151971b. [Cathedral Mountain Formation, USNM 702un.] Dyoros (Dyoros) extensus, new species: 11-14, Dorsal, ventral, posterior, and side views of a complete specimen, x 1, paratype USNM 151922c [Word Formation (Appel Ranch Member), USNM 715i.] 15-19, Ventral, anterior, posterior, side, and dorsal views, X 1, of a large, alate specimen, holotype USNM 153694a; 20-24, anterior, posterior, side, ventral, and dorsal views of an adult less alate than the preceding, x 1, paratype USNM 151915p; 25, hinge region of the preceding paratype, x 4, showing pseudodeltidium and chilidium; 26, 27, dorsal and ventral views of three small individuals, X 1, showing oblique spines and youthful alate form, paratypes (from top) USNM 153694b-d; 28, ventral view of a young specimen with most spines intact, X 1, para- type USNM 151914; 35-37, exterior, interior, and laterally tilted interior views of a large brachial valve, X 1, paratype USNM 153694e; 38, interior of another brachial valve, X 1.5, showing anteriorly expanding median septum, paratype USNM 153694f; 43, interior of the median part of an old adult, X 4, showing cardinalia, anderidia, endospines, and overgrown median septum, paratype USNM 153694g. [Word Formation (Willis Ranch Member), USNM 706c] 29, 30, Ventral and dorsal views of an immature specimen, x 1, paratype USNM 15191 Id; 31, dorsal views of two specimens smaller than the preceding, x 1, and showing strong alation, paratype USNM 15191 If, e; 32, interior of a large pedicle valve, X 1.5, showing muscle scars and median elevations, paratype USNM 153695a; 39, interior of another adult brachial valve, valve, x 1, paratype USNM 153695b; 40, 41, interior and laterally tilted views of the preceding paratype, X 2, showing endospinose median septum, anderidia, and cardinalia; 42, posterior view of the preceding specimen, x 3, showing the cardinal process; 44, interior of an old adult brachial valve, x 2, showing anterior thickening of the median septum, paratype USNM 153695c [Word Formation (Lens between the Willis Ranch and Appel Ranch members), USNM 706b.] 33, 34, Interior and laterally tilted views of an old adult, X 1, showing endospinose median septum, paratype USNM 153696. [Word Formation (Appel Ranch Member), USNM 722t.] NUMBER 19 1883 PLATE 48S.-Dyoros (Dyoros) 1884 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 484 Dyoros (Dyoros) Dyoros (Dyoros) hillanus (Girty): 1, 2, Mould of the brachial valve and plasticine cast prepared from it, X 1, paratype USNM 118518c; 3, 4, side and ventral views of the pedicle valve, X 1, lectotype USNM 118518a; 5, ventral view of another, smaller pedicle valve, X 1, paratype USNM 118518b. [Capitan Formation, USGS 2926 (green).] Dyoros (Dyoros) intrepidus, new species: 6-10, Dorsal, ventral, side, anterior, and posterior views of a complete specimen, x 1, paratype USNM 153697a; 11, interarea of the preceding paratype, X 4, showing cardinal process and pseudodeltidium; 12, interior of the brachial valve, X 2, para- type USNM 152794b; 13, posterior of the preceding specimen, x 4, showing cardinal process; 14, 15, laterally tilted and interior views of another brachial valve having a high median septum, X 2, paratype USNM 152794a; 16, interior of the brachial valve, X 2, paratype USNM 153697c [Bell Canyon Formation (Hegler Member), USNM 731.] 17-21, Dorsal, posterior, anterior, side, and ventral views of a complete specimen, x 1, holotype USNM 152795a; 22, dorsal view of the preceding specimen, X 1.5; 23, 24, interior of the pedicle valve, X 1, X 1.5, paratype USNM 152795b. [Bell Canyon Formation (Rader Member), USNM 725g.] 25-29, Side, ventral, dorsal, anterior, and posterior views of a small, complete specimen, X 1, paratype USNM 152796e; 30, interior of the pedicle valve, X 1.5, paratype USNM 152796c; 31, 32, interior of the brachial valve, x 1, X 2, paratype USNM 152796b. [Bell Canyon Formation (Rader Member), USNM 725f.] Dyoros (Dyoros) subliratus (Girty): 33-37, Ventral, side, posterior, anterior, and dorsal views of a complete specimen, x 1, hypotype USNM 151960. [Bell Canyon Formation, AMNH 524.] Dyoros (Dyoros) planiextensus, new species: 38-42, Dorsal, ventral, anterior, posterior, and side views of the holotype, X 1, USNM 152064a; 53, part of the interarea of the holotype, X 4, showing the pseudodeltidium and chilidium; 43-47, ventral, posterior, anterior, dorsal, and side views of another complete specimen, x 1, paratype USNM 152064d; 48-52, ventral, dorsal, an- terior, posterior, and side views of another paratype, X 1, USNM 152064m; 54, dorsal view of a young adult, X 1, paratype USNM 152064e; 55, dorsal view (upper left) of paratype USNM 152064h, ventral and dorsal views (middle and lower left) of immature paratype USNM 152064g, and ventral and dorsal views (right) of very young adult paratype USNM 152064i, all X 1; 56, 57, interior of a pedicle valve, showing the muscle scars, X 1, paratype USNM 153699a; 58, interior of another pedicle valve interior, X 1.5, paratype USNM 153699b; 59, interior of part of a pedicle valve, X 1.5, showing teeth and pseudodeltidium, paratype USNM 153699c; 60, interior of a brachial valve, X 2, showing cardinalia and anderidia, paratype USNM 153699d; 61, 62, interior of a young brachial valve, x 1, X 2, showing beginning of development of endospines, paratype USNM 153699c [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1885 PLATE 484,-Dyoros (Dyoros) 1886 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 485 Dyoros (Dyoros) Dyoros (Dyoros) robustus, new species: 1-5, Posterior, ventral, anterior, interior, and side views of a large pedicle valve, X 1, holotype USNM 151992a; 6-9, ventral, anterior, interior, and posterior views of another pedicle valve, x 1, paratype USNM 151992b; 10-12, posterior, interior, and exterior views of an incomplete brachial valve, X 1, paratype USNM 151992c [Bell Canyon Formation (Hegler Member), USNM 731.] Dyoros (Dyoros) intrepidus, new species: 13-17, Ventral, side, anterior, posterior, and dorsal views of a complete specimen, x 1, paratype USNM 153698a; 18-22, ventral, side, anterior, dorsal, and posterior views of another complete specimen, x 1, paratype USNM 153698b; 23, dorsal view of the preceding paratype, X 2; 24, interarea of the preceding, showing the pseudo- deltidium and chilidium, X 4; 25, 26, ventral and dorsal views of an alate specimen, X 1, para- type USNM 153698c; 27, 28, interior and exterior of an alate pedicle valve, X 1, paratype USNM 153698d; 29, interior of the preceding pedicle valve, X 2; 30, 31, exterior and interior of another pedicle valve, X 1, paratype USNM 153698e; 32, exterior of a small pedicle valve, X 1, paratype USNM 153698f; 33, 34, interior of the brachial valve, X 1, X 3, paratype USNM 153698g. [Bell Canyon Formation (Hegler Member), USNM 731.] Dyoros (Dyoros) subliratus (Girty): 35, Ventral view of a small pedicle valve, X 1, paratype USNM 118519b; 36, 37, ventral and side views of a large pedicle valve, x 1, lectotype USNM 118519a. [Capitan Formation (Bell Canyon equivalent), USGS 2930 (green).] Dyoros (Dyoros) planiextensus, new species: 38, Interior of a brachial valve with moderately developed endospines, X 1, paratype USNM 153699f; 39, interior of a well thickened adult, X 1, paratype USNM 153699g; 40, interior of the preceding specimen, X 2, showing median septum; 41, cardinalia of the preceding, showing anderidia, X 3; 42, median portion of a young brachial valve, X 3, showing median septum, endospines, and well developed anderidia, paratype USNM 153699h; 43, 44, another youthful brachial valve, X 1, X 3, showing incipient develop- ment of median septum and anderidia, paratype USNM 153699i; 45-47, views tilted posteriorly, interior, and tilted laterally to show median septum, endospines, and anderidia, X 1, paratype USNM 153699J; 48, interior of the preceding specimen, X 2; 49, median portion of a young adult, x 2, showing well developed anderidia, paratype USNM 153699k; 50, 51, posterior and interior views of a well formed adult, X 3, showing cardinal process, median septum, endospines, and anderidia, paratype USNM 153699-1. [Word Formation (lens between Willis Ranch and Appel Ranch members), USNM 706b.] NUMBER 19 1887 PLATE 485,-Dyoros (Dyoros) 1888 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 486 Dyoros (Dyoros) Dyoros (Dyoros) tenuis, new species: 1, Dorsal view of four immature specimens, X 1, showing transverse and alate form, paratype USNM 151996J, k, f, i, from left to right; 2-6, ventral, side, posterior, anterior, and dorsal views, x 1, holotype, USNM 151996a; 7, dorsal view of the holo- type, X 2; 8, pseudodeltidium and chilidium of the holotype, X 4; 9-13, ventral, posterior, an- terior, dorsal, and side views, X 1, paratype USNM 151996c; 14, 15, pedicle valve interior, X 1, X 2, showing thickened muscle region, paratype USNM 151996-1; 16, 17, interior of another pedicle valve, x 1, showing well developed muscle scars, paratype USNM 151996m; 18, interior of an alate pedicle valve with internal features poorly developed, x 1, paratype USNM 151996n; 19, 20, interior of an obese brachial valve, x 1, X 2, showing exaggerated internal structures, paratype USNM 151996o; 21, 22, laterally tilted and interior views of a large brachial valve, X 1, paratype USNM 151996p; 23, interior of the preceding specimen, X 2, showing anderidia and endospines; 24, interior of another brachial valve, X 1, paratype USNM 151996q; 25, 26, laterally tilted and interior views of the preceding paratype, X 2, showing anderidia and endospines; 27, posterior view of the cardinal process of the preceding specimen, X 4. [Word Formation (Willis Ranch Member-lower), USNM 706.] Dyoros (Dyoros) transversus, new species: 28, Dorsal view of an immature specimen, X 1, para- type USNM 151980c; 29-33, ventral, anterior, posterior, side, and dorsal views of an alate specimen, X 1, paratype USNM 153700d; 34-38, ventral, anterior, posterior, side, and dorsal views of another alate specimen with remnants of spine on the posterior margin, X 1, paratype USNM 153700b; 39, 40, interior and exterior of a pedicle valve, x 1, paratype USNM 151980t; 41, 42, dorsal and ventral views of a young alate specimen, x 1, paratype USNM 151980h; 43, dorsal and ventral views of a strongly alate young adult, x 1, paratype USNM 151980w; 46, dorsal and ventral views of a moderately alate specimen, X 1, paratype USNM 153700c; 47-51, dorsal, ventral, posterior, side, and anterior views of a large alate specimen, X 1, holo- type USNM 151980a; 52, 53, exterior and interior views of an alate pedicle valve, X 1, paratype USNM 151980s; 54, dorsal view of a young, strongly alate specimen, X 1, paratype USNM 151980e; 55-57, interior, posterior, and exterior views of an alate brachial valve, X 1, paratype USNM 151980m; 58-60, interior, posteriorly tilted, and exterior views of another alate brachial valve, X 1, paratype USNM 151980n. [Road Canyon Formation, USNM 707c] Dorsal view of an alate specimen, x 1, paratype USNM 153701. [Road Canyon Formation, USNM 721j.] Interior of a strongly endospinose, alate brachial valve, X 1, paratype USNM 151976 (for additional views of this see plate 487: figure 3). [Road Canyon Formation, USNM 703c] Dorsal view of a pedicle valve exterior, x 1, paratype USNM 153702. [Road Canyon Formation, USNM 710z.] 64-67, Exterior, laterally tilted, interior, and posterior views of a large brachial valve, x 1, paratype USNM 151997d. [Road Canyon Formation, USNM 703d.] NUMBER 19 1889 PLATE 486.-Dyoros (Dyoros) 1890 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 487 Dyoros (Dyoros) and Dyoros (Lissosia) Dyoros (Dyoros) transversus, new species: 1, 2, Interior, X 1, X 15, showing lateral endospinose thickenings, paratype USNM 153703a. [Road Canyon Formation, USNM 724c] 3, 4, Interior and laterally tilted views of a brachial valve, X 2, showing anterior endospinose thickenings, and anderidia, paratype USNM 151976 (for additional view of this specimen, see plate 486: figure 62). [Road Canyon Formation, USNM 703c] 5, 6, Interior of an alate pedicle valve, X 1, X 1.5, showing lateral thickenings and extra tissue deposited around the adductor scars, paratype USNM 153704a; 7, 8, interior of a large brachial valve, X 1, X2, showing only a moderate development of the endospines, paratype USNM 153704b; 9, posterior of the preceding specimen showing the cardinal process, X 2. [Road Canyon Formation, USNM 726d.] 10, Interior, x 2, of a much thickened pedicle valve interior, paratype USNM 153700e; 11, in- terior of a brachial valve, X 2, showing anderidia and endospines, paratype USNM 153700f. [Road Canyon Formation, USNM 707c] 12, 13, Exterior and interior of a large pedicle valve, X 1, paratype USNM 153706a; 14, in- terior of the preceding paratype, X 2, showing lateral endospinose thickening; 15, 16, interior and exterior of a brachial valve, X I, paratype USNM 153706b; 17, interior of the preceding specimen, x 2, showing endospinose thickenings. [Cibolo Formation (Thin-bedded Zone of Udden), USNM 738-1.] Dyoros (Lissosia) concavus, new species: 18-22, Ventral, anterior, posterior, dorsal, and side views of a young adult having fine radial ornament, x 1, paratype USNM 152147h; 23-27, dorsal, ventral, side, posterior, and anterior views of another paratype, X 1, USNM 152147f; 28-32, ventral, posterior, side, anterior, and dorsal views of an adult, X 1, paratype USNM 152147b; 33-37, ventral, side, posterior, anterior, and dorsal views of a large, alate specimen, x 1, para- type USNM 152147a; 38-42, ventral, posterior, anterior, side, and dorsal views of well formed specimen, x 1, paratype USNM 152147d; 43, interior of a pedicle valve, X 1, paratype USNM 153706a; 44-46, interior, laterally tilted, and posterior views of a brachial valve, X 1, paratype USNM 153706b. [Word Formation (China Tank Member), USNM 706c] NUMBER 19 1891 PLATE 487.-Dyoros (Dyoros) and Dyoros (Lissosia) 1892 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 488 Dyoros (Lissosia) Dyoros (Lissosia) concavus, new species: 1-5, Ventral, side, anterior, posterior, and dorsal views of a complete specimen with radial ornament, x 1, holotype USNM 152144a; 6, 7, pedicle valve interior, X 1, X 1.5, paratype USNM 153707b; 8, 9, posteriorly tilted and interior views of an obese brachial valve, X 1, paratype USNM 153707c; 10-12, interior, posteriorly tilted, and laterally tilted views of the preceding paratype, X 2, showing thickening of median septum, and strong endospines; 13, 14, laterally tilted and interior views of another brachial valve, X 1, paratype USNM 153707e; 15, interior of the preceding specimen, X 2, showing anderidia and endospines; 16, interior of a pedicle valve, X 1.5, paratype USNM 153707f. [Word Formation (Willis Ranch Member, lower), USNM 706.] 17-21, Ventral, dorsal, posterior, side, and anterior views of a small adult, X 1, paratype USNM 152149e; 22, 23, interior of a brachial valve, X 1, X 2, paratype USNM 153708a; 24, 25, preceding specimen, X 2, tilted posteriorly and laterally to show median septum and endospines; 26, 27, interior and laterally tilted views of a brachial valve, x 1, paratype USNM 153708b; 28, 29, laterally tilted and interior views of the preceding specimen, X 2, showing anderidia. [Word Formation (Willis Ranch Member, top), USNM 706c] Dyoros (Lissosia) parvus, new species: 30-34, Ventral, side, anterior, posterior, and dorsal views of a complete specimen, x 1, holotype USNM 152154a; 35, dorsal view of the beak region, X 4, showing pseudodeltidium and cardinal process of the holotype; 36-40, ventral, posterior, anterior, side, and dorsal views of a small paratype, X 1, USNM 152154e; 41, 42, interior of the pedicle valve, X 1, X 2, paratype USNM 153709a; 43, interior of the brachial valve, X 1, paratype USNM 153709b; 44, laterally tilted view of the preceding specimen, x 2; 45, interior of the preceding brachial valve, X 3, showing anderidia. [Road Canyon Formation, USNM 707c] Dyoros (Lissosia) vagabundus, new species: 46-50, Ventral, posterior, dorsal, side, and anterior views of a complete specimen, x 1, holotype USNM 152163a; 51-55, ventral, anterior, posterior, dorsal, and side views of another paratype, X 1, USNM 152163d; 56, interior of the pedicle valve, X 1, paratype USNM 152163c; 57, 58, posteriorly tilted and interior views of a brachial valve, X 2, paratype USNM 152163f; 59, posterior view of part of the preceding, x 4, showing the cardinal process. [Cathedral Mountain Formation, USNM 702.] NUMBER 19 1893 PLATE 488.-Dyoros (Lissosia) 1894 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 489 Dyoros (Lissosia) and Dyoros (Tetragonetes) Dyoros (Lissosia) vagabundus, new species: 1, Dorsal view of three immature specimens, X 1, paratype USNM 152166k, j, i; 2-6, anterior, ventral, posterior, dorsal, and side views of a small, complete specimen, X 1, paratype USNM 152166e; 7-11, ventral, dorsal, side, anterior, and pos- terior views of another complete specimen, x 1, paratype USNM 152166a; 12, interior of a young brachial valve, x 1, paratype USNM 153710d; 13, dorsal view of two pedicle valves preserving some of their spines, X 1, paratype USNM 153710a, b; 14, interior of a brachial valve, X 1, paratype USNM 153710c; 15, 16, laterally tilted and interior views of the preceding brachial valve, X 2; 17, median portion of a young brachial valve (illustrated in figure 12), X 4, showing anderi- dia and median septum, paratype USNM 153710d. [Cathedral Mountain Formation, USNM 702b.] 18, 19, Exterior and interior of a pedicle valve, x 1, paratype USNM 152162a; 20, 21, exterior and interior of a large pedicle valve, X 1, paratype USNM 152162b. [Cathedral Mountain Forma- tion, USNM 702.] 22, Interior of another brachial valve with distally expanded median septum, X 1, paratype USNM 153711a; 23, 24, interior and laterally tilted views of the preceding specimen, X 2, showing anderidia and endospines; 25, posterior view of the preceding brachial valve, X 3, showing the cardinal process. [Cathedral Mountain Formation, USNM 721 u.] Dyoros (Tetragonetes) auriculatus, new species: 26-29, Ventral, dorsal, anterior, and side views of a complete specimen, X 1, holotype USNM 152180f; 30, 34, posterior and dorsal views of a com- plete specimen, x 1, paratype USNM 152180e; 31, dorsal exterior of the holotype, X 2; 33, ex- terior of a small pedicle valve having strong radial ornament, X 1, paratype USNM 152180h; 35, exterior of another radially ornamented pedicle valve, X 1, paratype USNM 152180k; 36-38, interior, posteriorly tilted, and exterior views of an average pedicle valve, x 1, paratype USNM 152180b; 39, interior of a pedicle valve, X 2, paratype USNM 152180J; 40, interior of a brachial valve, X 1, paratype USNM 152180n; 41, 42, laterally tilted and interior views of the preceding paratype, X 2, showing anderida and modest endospines; 43, interior of another brachial valve, X 2, paratype USNM 152180m. [Cherry Canyon Formation (Getaway Member), USNM 728.] 32, Exterior of a pedicle valve, x 2, showing strong radial ornament, paratype USNM 153714. [Word Formation (Appel Ranch Member), USNM 722t.] Dyoros (Tetragonetes) complanatus, new species: 44-48, Dorsal, posterior, anterior, ventral, and side views of a complete specimen, X 1, holotype USNM 153712a; 49, dorsal view of the preceding, X 2; 50, 51, exterior and interior of a brachial valve, X 1, paratype, USNM 153712b; 52, interior of the preceding brachial valve, X 2, showing well developed anderidia and poorly developed median septum. [Cherry Canyon Formation (Getaway Member), Moore locality 31.] 53, Interior of another, but obese, brachial valve, x 1, paratype USNM 153713a; 54, 55, interior and laterally tilted views of the preceding paratype, X 2, showing highly developed anderidia and median septum; 56, posterior of the preceding specimen, X 4, showing the cardinal process; 57, 58, interior of the pedicle valve, X 1, X 2, showing median septum and muscle scars, paratype USNM 153713b. [Cherry Canyon Formation (Getaway Member), AMNH 600.] NUMBER 19 1895 PLATE 489.- Dyoros (Lissosia) and Dyoros (Tetragonetes) 1896 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 490 Dyoros (Tetragonetes) Dyoros (Tetragonetes) quadrangulatus, new species: 1-5, Ventral, side, anterior, posterior, and dorsal views of the holotype, x 1, USNM 153715a; 6-9, anterior, posterior, side, and ventral views of a pedicle valve, X 1, paratype USNM 152187b; 10, interior of the preceding pedicle valve, X 1.5, showing muscle scars; 11, exterior of a small pedicle valve, X 1, showing traces of radial ornament, paratype USNM 152187k; 12, 13, laterally tilted and interior views of a brachial valve, X 2, showing anderidia and serrate median septum, paratype USNM 153715b; 14, median portion of another brachial valve, X 3, showing endospinose median septum and well developed anderidia, paratype USNM 153715c; 15, interior of another brachial valve with slender anderidia and median septum, x 2, paratype USNM 1537I5d; 16, posterior of the preceding paratype, X 3, showing the cardinal process; 17, interior of a pedicle valve, x 1.5, paratype USNM 152187f; 18, 19, interior and posteriorly tilted views of another pedicle valve, x 1, paratype USNM 153715f. [Word Formation (Appel Ranch Member), USNM 715i.] Dyoros (Tetragonetes) wordensis, new species: 20-24, Dorsal, anterior, posterior, side, and ventral views, X 1, of the holotype USNM 152026c; 25-29, dorsal, side, anterior, posterior, and ventral views of a complete paratype, X 1, USNM 152026g; 30, posterior of interarea, X 4, showing pseudodeltidium and chilidium, paratype USNM 152026a; 31, interior of the pedicle valve, X 2, paratype USNM 152026-1; 32, 33, interior and posteriorly tilted views, X 2, of the brachial valve, showing anderidia and endospines, paratype USNM 152026m; 34, 35, interior and laterally tilted views, X 2, of another brachial valve, showing anteriorly thickened median septum, para- type USNM 152026n; 36, posterior view of the preceding specimen, X 4, showing the cardinal process. [Word Formation (Willis Ranch Member), USNM 706c] Dyoros (Tetragonetes) rectangulatus, new species: 37-41, Ventral, posterior, anterior, side, and dorsal views of a complete specimen, X 1, paratype USNM 153716. [Cathedral Mountain Forma- tion, AMNH 500G.] 42-46, Anterior, posterior, side, dorsal, and ventral views of another paratype, X 1, USNM 153717; 47, posterior view of the preceding specimen, x 3, showing cardinal process. [Road Can- yon Formation, USNM 703a.] 48, 49, Ventral and dorsal views of a paratype, x 1, preserving some of its long spines, paratype USNM 152043. [Cathedral Mountain Formation, USNM 703a1.] 50-52, Dorsal, side, and ventral views of a small paratype, x 1, USNM 153718a; 58-61, posterior, side, dorsal, and ventral views of a large paratype, X 1, USNM 153718b. [Cathedral Mountain Formation, USNM 702.] 53-57, Dorsal, side, posterior, anterior, and ventral views of a complete specimen, x 1, holotype USNM 152039a; 62, interior of a pedicle valve, x 2, paratype USNM 152039e; 63, interior of a young brachial valve, x 2, paratype USNM 152039f; 64, posterior of the preceding specimen, X 4, showing the cardinal process; 65, 66, laterally tilted and interior views of a brachial valve, X 2, showing well formed anderidia, paratype USNM 152039g. [Cathedral Mountain Formation, USNM 702b.] Dyoros (Tetragonetes) subquadratus, new species: 67-71, Anterior, ventral, posterior, dorsal, and side views of a complete specimen, x 1, holotype USNM 151988a; 72, exterior of the preceding, X 4, showing fine radial lines; 73-77, side, anterior, dorsal, posterior, and ventral views of another complete individual, x 1, paratype USNM 151988b (for interior views, see plate 491: figures 20- 32). [Cherry Canyon Formation (Getaway Member), USNM 728 = AMNH 512.] NUMBER 19 1897 PLATE 490.-Dyoros (Tetragonetes) 1898 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 491 Dyoros (Tetragonetes), Lissochonetes, and Quadrochonetes Dyoros (Tetragonetes) solidus, new species: 1, Dorsal views of four immature specimens, X 1, paratypes USNM 152015J, i, k, g; 2, ventral, anterior, side, posterior and dorsal views of three paratypes larger than the preceding ones, X 1, USNM 152015h, 1, m; 3-7, ventral, posterior, an- terior, dorsal, and side views of a large adult, x 1, holoype USNM 152015a; 8-12, dorsal, posterior, anterior, ventral, and side views, X 1, of another large paratype, USNM 152015p; 13, interior of a pedicle valve, X 2, paratype USNM 153719a; 14, interior of a brachial valve, X 2, paratype USNM 153719b; 15, 16, interior and laterally tilted views of a brachial valve, X 2, paratype USNM 153719c; 17, posterior of the preceding specimen, X 4, showing the cardinal process; 18, 19, in- terior and exterior of a brachial valve, x 1, paratype USNM 153720. [Road Canyon Formation, USNM 703d.] Dyoros (Tetragonetes) subquadratus, new species: 20-23, Posterior, anterior, side, and ventral views of a large pedicle valve, x 1, paratype USNM 151988h; 24, interior, X 1.5, of the preceding specimen; 25-27, anterior, ventral, and side views of another pedicle valve, X 1, paratype USNM 151988i; 28, interior, X 1.5, of the preceding specimen; 29, interior of a brachial valve, X 2, para- type USNM 151988k; 30-32, posterior and laterally tilted views, X 2, and posterior view, X 3, of another brachial valve, showing the anderidia, paratype USNM 151988J (for exterior views of this species, see plate 490: figures 67-77). [Cherry Canyon Formation (Getaway Member), USNM 728 = AMNH 512.] Dyoros (Tetragonetes) strigosus, new species: 33-37, Ventral, dorsal, side, posterior, and anterior views of a large specimen, x 1, holotype USNM 152036a; 38-42, ventral, dorsal, side, anterior, and ventral views of a smaller specimen than the preceding, X 1, paratype USNM 152036b. [Road Canyon Formation, USNM 703d.] Lissochonetes parvisulcatus, new species: 43, Standard views of two specimens, paratype on left and holotype on right, x 1; 44, dorsal view, X 2, of the holotype USNM 151993a; 45, dorsal views of a paratype, x 2, USNM 151993c [Gaptank Formation (œ/dd' if 38 '®&&œ* 39 28  < ,-4<" r-*-^.>TV'  pi;': h . mk ^.^,;, ir.flftr $&/ 59 1910 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 497 Neochonetes, Dyoros (Tetragonetes), and Lamellosia Neochonetes dominus (R. H. King): 1-5, Anterior, dorsal, posterior, side, and ventral views of a complete specimen, x 1, hypotype USNM 153738b; 6-10, anterior, ventral, side, dorsal, and pos- terior views of another complete specimen, x 1, hypotype USNM 153738a; 11, interior of the pedicle valve of the preceding specimen, X 2; 12, interior of the brachial valve of the preceding specimen, x 2; showing small anderida; 13, posterior of another complete specimen, X 4, show- ing cardinal process and pseudodeltidium, hypotype USNM 153738c; 14, interior of a thickened pedicle valve, X 2, hypotype USNM 153738d; 15, interior of a young pedicle valve, X 2, showing fine endospines, hypotype USNM 153738e; 16, exterior of a pedicle valve, showing the fine radial costellae, X 4, hypotype USNM 153738f; 17, laterally tilted brachial valve interior, X 2, showing median septum and well formed anderidia, hypotype USNM 153738g; 18, posterior of the preced- ing specimen, showing the cardinal process, x 4. [Bend Formation (Marble Falls Member), on Texas State Highway 81, 2.7 miles south of San Saba, Texas.] Neochonetes puebloensis (R. H. King): 19-23, Anterior, ventral, side, posterior, and dorsal views of a large and complete specimen, x 1, hypotype USNM 153739a; 24, exterior of part of the brachial valve of the preceding specimen, X 4, showing the costellae; 25, interior of the brachial valve, X 2, showing anderidia and anteriorly thickened median septum, hypotype USNM 153739b. [Putnam Formation (Coleman Junction Member), USNM 766.] 26, Interior of a pedicle valve, X 1.5, showing muscle scars, hypotype USNM 152124. [Pueblo Formation, one mile south of Camp Colorado, Coleman County, Texas.] Neochonetes meekanus (Girty): 27, Interior, X 1.5, of the brachial valve, showing well formed anderidia, hypotype USNM 152119a; 28, interior of a somewhat thickened brachial valve, X 1.5, showing anderidia and endospines, hypotype USNM 152119b; 29, posterior view of the preceding specimen, showing the cardinal process, X 3; 30, interior of an obese brachial valve, X 1.5, hypo- type USNM 152119c [Hughes Creek Formation, U. S. Highway 75, five miles south of Dawson, Nebraska.] Dyoros (Tetragonetes) giganteus, new species: 31, 32, Interior and exterior of a large brachial valve, X 1, paratype USNM 153736a; 33, posterior view of the preceding brachial valve, X 4, showing strongly developed anderidia; 34, 35, exterior and interior of the pedicle valve, X 1, paratype USNM 153736b. [Cathedral Mountain Formation, USNM 726u.] Lamellosia lamellosa, new species: 36, Posterior, dorsal, side, anterior, and ventral views of a complete specimen, x 1, holotype USNM 153740a; 37, dorsal view of the preceding specimen, X 2, showing lamellosc exterior; 38, 39, exterior, X 1, and interior, X 2, of a pedicle valve show- ing lamellose exterior, paratype USNM 153740b; 40, exterior of another pedicle valve, X 2, show- ing crowded, concentric lamellate, paratype USNM 153740c; 41, 42, exterior of a pedicle valve with strong lamellae, X 1, X 2, paratype USNM 153740d; 43, hinge region of the preceding specimen, X 2. [Bell Canyon Formation (Hegler Member), USNM 732a.] NUMBER 19 1911 PLATE 497.-Neochonetes, Dyoros (Tetragonetes), and Lamellosia 1912 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 498 Rugaria, Leurosina, Dyoros (Tetragonetes), "Chonetes," and Dyoros (Dyoros) Rugaria hessensis (R. E. King): 1-5, Posterior, ventral, side, dorsal, and anterior views of a com- plete specimen, x 3, paratype YPM 10820b; 6, dorsal view of an imperfect specimen, X 3, para- type T10589; 7, dorsal view of a complete specimen, X 1, lectotype YPM 10820a; 8-12, ventral, anterior, side, posterior, and dorsal views, X 3, of the preceding lectotype. [Hess Formation (Taylor Ranch Member), R. E. King locality 107.] Leurosina sinesulca (Stehli): 13-17, Posterior, ventral, side, anterior, and interior views of a large pedicle valve, x 1, hypotype USNM 153741a; 18, interior of the preceding specimen, X 2; 19-23, interior, anterior, side, posterior, and ventral views of another pedicle valve, X 1, hypotype USNM 153741b; 24, 25, ventral and interior views of a pedicle valve, X 1, hypotype USNM 153741c; 26, posterior of the interarea of the preceding specimen, X 4, showing teeth and pseudodeltidium; 27, exterior of a brachial valve, X 1, hypotype USNM 153741d; 28, 29, laterally tilted and interior views of the preceding specimen, x 2, showing median septum and anderidia; 30, exterior of another brachial valve, x 1, hypotype USNM 153741 œ; 31, 32, laterally tilted and interior views of a brachial valve showing well developed anteridia, x 2, hypotype USNM 153741c [Bone Spring Formation, USNM 728c] 44, Interior of the brachial valve, x 2, showing a modestly developed median septum and strong anderidia, hypotype USNM 153742a; 45, 46, interior of another brachial valve, X 1, X 2, showing a strongly developed median septum, hypotype USNM 153742b; 47, exterior of the pedicle valve, X 1, hypotype USNM 153742c; 48, interarea of the preceding specimen, x 2. [Bone Spring Forma- tion, AMNH 631.] Dyoros (Tetragonetes) subquadratus, new species: 33-37, Dorsal, anterior, side, posterior, and ventral views of a small individual, X 1, paratype USNM 151988d. [Cherry Canyon Formation (Getaway Member), USNM 728 = AMNH 512.] "Chonetes" verneuilianus R. E. King (not Norwood and Pratten) = Dyoros? species: 38, dorsal view of a complete specimen, x 1, figured specimen YPM 10792; 39-43, dorsal, posterior, anterior, ventral, and side views of the preceding specimen, X 2, (see Chonetinella for discussion). [Lenox Hills Formation, R. E. King locality 75.] Dyoros (Dyoros) hillanus (Girty): 49-53, Posterior, anterior, dorsal, ventral, and side views of a complete specimen, X 1, hypotype USNM 153743a; 54, dorsal view of the preceding specimen, X 2; 55, interior of a pedicle valve, X 1, hypotype USNM 153743b; 56, 57, dorsal and side views of a small specimen, x 1, hypotype USNM 153743c [Bell Canyon Formation (Lamar Member), USNM 728p.] Dyoros (Dyoros) intrepidus, new species: 58, Exterior of an alate pedicle valve, X 1, paratype USNM 153744a; 59, interior of the preceding specimen, x 2; 60, exterior of a brachial valve, X 1, paratype USNM 153744b; 61, interior of the preceding brachial valve, X 2, showing anderidia and median septum; 62, interarea of a nearly complete specimen, X 3, showing the pseudodel- tium and chilidium, paratype USNM 153744c. [Bell Canyon Formation (Rader Member), USNM 740a.] NUMBER 19 1913 PLATE 498.-Rugaria, Leurosina, Dyoros (Tetragonetes), "Chonetes, and Dyoros (Dyoros) 34 37 35 if ^k 36 '4 -w-v 59 ?\/f 1914 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 499 Dyoros (Tetragonetes) and Rugaria Dyoros (Tetragonetes) complanatus, new species: 1-5, Dorsal, posterior, anterior, side, and ventral views of a complete specimen, X 1, paratype USNM 152017b; 6, dorsal view of two immature specimens, X 1, paratypes USNM 152017i, f; 7-11, dorsal, anterior, posterior, side, and ventral views of a paratype, X I, USNM 152017a; 12, dorsal view of another paratype, X 1, USNM 152017d; 13, interior of the pedicle valve, X 2, paratype USNM 152017k; 14, interior of brachial valve, X 2, showing anderidia, paratype USNM 152017-1; 15, 16, laterally tilted and interior views of another brachial valve, X 2, paratype USNM 152017m; 17, posterior view of the cardinal process, X 4, of the preceding specimen. [Cherry Canyon Formation (Getaway Member), USNM 732.] Dyoros (Tetragonetes) giganteus, new species: 18-22, Dorsal, anterior, posterior, side, and ventral views of the holotype, X 1, USNM 152032a; 23, 24, ventral and interior views of a pedicle valve, X 1, paratype USNM 152032b; 25, ventral view of a small specimen, x 1, paratype USNM 152032c [Cathedral Mountain Formation, USNM 708u.] 26-28, Interior, side, and ventral view of a large pedicle valve, X I, paratype USNM 153745. [Cathedral Mountain Formation, USNM 735c] 29, Ventral view of another pedicle valve, X 1, paratype USNM 152031a; 30, interior of the preceding specimen, X 1.5. [Cathedral Mountain Formation, USNM 702b.] Interior of the brachial valve, X 2, showing anderidia and thin median septum, paratype USNM 153746. [Cathedral Mountain Formation, USNM 721u.] Ventral view of a small pedicle valve, x 1, paratype USNM 152029. [Cathedral Mountain Formation, USNM 702.] Dyoros (Tetragonetes) lateralis, new species: 33-37, Ventral, anterior, posterior, side, and dorsal views, X 1, of the holotype USNM 152798a. [Cathedral Mountain Formation, USNM 71 lq.] Dyoros (Tetragonetes) planus, new species: 38-42, Dorsal, side, anterior, posterior, and ventral views of a complete specimen, X 1, paratype USNM 152008c; 43, dorsal view of two immature specimens, X 1, paratypes USNM 152008i, h; 44-48, dorsal, posterior, side, anterior, and ventral views of the paratype, X 1, USNM 152008a; 65, posterior view of the interarea of the preceding paratype, X 4, showing the cardinal process and pseudodeltidium; 49-53, ventral, posterior, an- terior, side, and dorsal views, X 1, of a paratype USNM 152008e; 54-58, ventral, side, anterior, posterior, and dorsal views, X 1, of the holotype USNM 152008b; 59, dorsal view of another paratype, X 2, USNM 152008J; 60, interarea of the preceding specimen, X 3, showing the cardinal process and pseudodeltidium; 61, interior of the pedicle valve, X 2, paratype USNM 152008-1; 62, interior of the brachial valve, X 2, showing delicate endospines and septum, paratype USNM 152008m; 63, posterior view of the preceding paratype X 4, showing the cardinal process; 64, interior of another brachial valve, X 2, showing anderidia, paratype USNM 152008n. [Cathedral Mountain Formation, USNM 71 lq.] Dyoros (Tetragonetes) telragonus, new name (for Chonetes quadratus R. E. King): 66, 68, Ventral and side views of the holotype, YPM 10830; 67, ventral view of the holotype, X 2. [Kaibab For- mation, Bass Ranch, Grand Canyon, Arizona.] Dyoros (Tetragonetes) cf. D. (T.) tetragonus, new name: 69, Ventral view of a small specimen, X 1, figured specimen YPM 10833 (R. E. King, plate 9: figure 10). [Word Formation (Appel Ranch Member), R. E. King locality 247.] Rugaria hessensis (R. E. King): 70, 71, Exterior and interior of a brachial valve, X 2, hypotype USNM 153747. [Cathedral Mountain Formation, USNM 721u.] NUMBER 19 1915 PLATE 499.-Dyoros (Tetragonetes) and Rugaria 1916 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 500 Chonetinella, Dyoros (Dyoros), and Leurosina Chonetinella crassipaiua, new species: 1, Dorsal views of two specimens, X 1, holotype (top) and paratype USNM 151883b, a; 2, dorsal view of two more paratypes, X 1, USNM 151883e, d; 3, ventral, anterior, side, posterior, and dorsal views, X 2, holotype (top) and paratype USNM 151883a; 4, dorsal, posterior, side, anterior, and ventral views, X 2, paratypes USNM 151883e (top) and 5, 6, dorsal and side views, X 4, of paratype USNM 151883a; 7, 8, dorsal and side views, X 4, of the holotype; 9, interior of the pedicle valve, X 2, paratype USNM 151882a; 10, interior of the brachial valve, x 4, paratype USNM 151882b. [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] Chonetinella species 2: 11, 12, Exterior of two pedicle valves, X 3, figured specimens USNM 152790a, b (for additional views, see plate 480: figure 36). [Neal Ranch Formation (top 15 feet of bed 2 of P. B. King), USNM 701.] Chonetinella victoriana (Girty): 13, 14, Interior and posterior views of a brachial valve, X 3, hypo- type USNM 153683-1; 15, 16, posterior and interior views of another brachial valve, x 3, showing anderidia, paratype USNM 153683f; 17-19, laterally tilted, posterior, and interior views of a third brachial valve, x 3, showing anderidia and short median septum, paratype USNM 153683k. [Bone Spring Formation, USNM 728L] Dyoros (Dyoros) extensiformis, new species: 20-24, Ventral, posterior, dorsal, side, and anterior views, X 1, of the holotype, USNM 151972a; 25-29, posterior, ventral, dorsal, side and anterior views, X 1, of a small paratype USNM 151972b; 30, dorsal view of the posterior of the preceding paratype, X 3, showing the cardinal process; 31, interior of the brachial valve, X 2, paratype USNM 151972d; 32, interior of the pedicle valve, X 2, paratype USNM 151972c [Road Canyon Formation, USNM 702c] Leurosina sinesulca (Stehli): 33, Exterior of a pedicle valve, X 1, hypotype USNM 153751a; 34, interior of the preceding specimen, x 2; 35, 36, exterior, X 1, and interior, x 2, of another ped- icle valve, hypotype USNM 153751b; 37, 38, interior and laterally tilted views of a brachial valve, X 2, showing serrate median septum and anderidia, hypotype USNM 153751c; 39, posterior of the preceding specimen, X 4, showing the cardinal process; 40, exterior of the preceding specimen, X 1. [Bone Spring Formation, USNM 728c] Chonetinella ciboloensis, new species: 41, Ventral, posterior, side, anterior, and dorsal views, X 1, of the paratype USNM 153752a (top) and holotype USNM 153752b; 42-45, ventral, side, anterior, and dorsal views of the paratype, X 2; 46-49, anterior, side, dorsal and ventral views of the holo- type, X 2. [Cibolo Formation (Breccia Zone of Udden), AMNH 703.] NUMBER 19 1917 PLATE 500.-Chonetinella, Dyoros (Dyoros), and Leurosina 1918 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 501 Dyoros (Dyoros), Chonetinella, and Micraphelia Dyoros (Dyoros), transversus, new species: 1, Dorsal view of a complete specimen, X 1, paratype USNM 153705a; 2, interior of the pedicle valve, X 1.5, showing lateral thickenings, paratype USNM 153705b; 3, 4, interior of the brachial valve, X 1, X 1.5, showing anteriorly thickened median septum and small anderidia, paratype USNM 153705c [Road Canyon Formation, USNM 732j.] Chonetinella gerontica, new species: 5-9, Dorsal, ventral, posterior, anterior, and side views of a complete specimen, x 1, holotype USNM 153753a; 10-14, posterior, anterior, ventral, side, and dorsal views of a damaged specimen, x 1, paratype USNM 153753b; 15, dorsal view of the pre- ceding, X 2; 16-18, side, ventral, and dorsal views of a small specimen, X 1, paratype USNM 153753c; 19-21, anterior, posterior, and ventral views of a well formed pedicle valve, X 1, para- type USNM 153753d; 22, ventral view of the preceding specimen, x2; 23, 24, interior of two bra- chial valves, X 2, showing anderidia and only a trace of a median septum, paratypes USNM 153753c f. [Road Canyon Formation, USNM 732j.] Micraphelia subalata, new species: 25, Posterior, ventral, side, anterior, and dorsal views of two complete specimens, X 1, holotype USNM 151890b (top) and paratype USNM 151890k; 26-28, side, dorsal, and anterior views of the holotype, X 2; 29-31, side, dorsal, and anterior views of the paratype, X 2. [Bell Canyon Formation (Rader Member), AMNH 410.] Dyoros (Dyoros) convexus, new species: 32-36, Ventral, posterior, side, dorsal, and anterior views of a strongly alate specimen, x 1, paratype USNM 153754d; 37-41, ventral, side, posterior, an- terior, and dorsal views of an obese adult, X 1, paratype USNM 153754a; 42-46, posterior, anterior, dorsal, ventral, and side views of a paratype, x 1, USNM 153754b; 51, interarea of the preceding specimen, x 4, showing the chilidium and pseudodeltidium; 47, 48, dorsal view of another alate specimen, x 1, X 2, paratype USNM 153754c; 49, 50, dorsal view of two small adults, X 1, para- types USNM 153754f, e; 52, 53, interior of two pedicle valves, x 1, paratypes USNM 153754g, h; 54, interior of a brachial valve, X 1, paratype USNM 153754i; 55-57, posteriorly tilted, interior, and laterally tilted views of the preceding paratype, X 2, showing septum, strong endospines, and weak anderidia; 58, interior of another brachial valve, x 1, paratype USNM 153754J; 59-61, laterally tilted, posteriorly tilted, and interior views of the preceding specimen, X 2. [Word For- mation (lens between that of 706b and the Appel Ranch Member), USNM 732c] NUMBER 19 1919 PLATE 501.-Dyoros (Dyoros), Chonetinella, and Micraphelia ^4* W^f tSP 1920 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY PLATE 502 Quadrochonetes, Undulella, Dyoros (Lissosia), Dyoros (Dyoros), and Chonetinetes Quadrochonetes praecursor, new species: 1, Ventral, posterior, side, anterior, and dorsal views of four specimens, X 1, paratypes (from top) USNM 152088d, c, b, and holotype USNM 152088a (bottom); 2, dorsal view of the holotype, x 3; 3-5, dorsal views, X 3, of paratypes USNM 152088b-d; 6-8, interior of three pedicle valves, X 3, paratypes USNM 152088e-g; 9, interior of a brachial valve, X 3, paratype USNM 152088h; 10, 11, interior and posterior views of another brachial valve, X 3, paratype USNM 152088i; 12, 13, interior and posterior views of a third brachial valve, X 3, paratype USNM 152088k. [Bone Spring Formation, AMNH 631.] Quadrochonetes girtyi Stehli: 14, Dorsal view of six specimens of small size, X 1, hypotypes (from top left) USNM 152091 i, h, g, f, c, b; 15, ventral view of three specimens preserving some of their spines, x 1, hypotypes USNM 153748a-c; 16, 17, exterior of a brachial valve, X 1, X 2, hypotype USNM 153721f; 18, 19, exterior of another brachial valve, X 1, X 2, hypotype USNM 153721d; 20-24, dorsal, posterior, ventral, side, and anterior views of a complete specimen preserving some of its spines, X 2, hypotype USNM 152091c; 25-29, posterior, anterior, side, dorsal, and ventral views of a large specimen, X 2, hypotype USNM 152091b; 30, 31, ventral view, X 1, of two hypotypes USNM 153721h and 152091d; 32, ventral view of a large specimen, X 2, hypotype USNM 153721c; 33, ventral view, X 2, of another hypotype USNM 152091k (for additional views of this species, see plate 491). [Bone Spring Formation, USNM 728f.] Undulella matutina, new species: 34, Dorsal view of a complete specimen, x 1, holotype USNM 153749a; 35-39, posterior, anterior, side, ventral, and dorsal views of the holotype, X 2; 40, 41, interior of the pedicle valve, X 1, X 3, paratype USNM 153749b; 42, 43, interior of the brachial valve, X 1, X 2, paratype USNM 153749c [Road Canyon Formation, USNM 732j.] Dyoros (Lissosia) concavus, new species: 44, Interior of the brachial valve, X 2, paratype USNM 153707a; 45, dorsal view of a complete specimen, x 2, showing radial ornament, holotype USNM 152144a (for additional views of the holotype, see plate 488: figures 1-5). [Word Forma- tion (Willis Ranch Member-lower), USNM 706.] Dyoros (Dyoros) vulgaris, new species: 46-50, Anterior, posterior, ventral, side, and dorsal views of an alate specimen, X 1, holotype USNM 153750a; 51-55, posterior, anterior, side, ventral, and dorsal views of another complete specimen, X 1, paratype USNM 153750b; 56-60, posterior, an- terior, ventral, dorsal, and side views of a third complete, alate individual, X 1, paratype USNM 153750c; 61, dorsal view of the preceding specimen, X 2; 62, interior of the brachial valve, X 3, showing sparse endospines and median septum, paratype USNM 153750d (for pedicle valve in- terior, see plate 42: figure 16). [Road Canyon Formation, USNM 732j.] Chonetinetes varians, new species: 63, Dorsal view of a complete specimen, x 4, holotype USNM 153677a (for additional views see plate 477: figures 49-53). [Bell Canyon Formation (Hegler Member), USNM 732a.] NUMBER 19 1921 PLATE 502.-Quadrochonetes, Undulella, Dyoros (Lissosia), Dyoros (Dyoros), and Chonetinetes ***** 56 46 -?r* ^njr:7 >J? f \'XU 51 ^49 50 57 53 52 55 1 60 Publication in Smithsonian Contributions to Paleobiology Manuscripts for serial publications are accepted by the Smithsonian Institution Press, sub- ject to substantive review, only through departments of the various Smithsonian museums. Non-Smithsonian authors should address inquiries to the appropriate department. If submission is invited, the following format requirements of the Press will govern the preparation of copy. Copy must be typewritten, double-spaced, on one side of standard white bond paper, with 1/a" top and left margin, submitted in ribbon copy with a carbon or duplicate, and accom- panied by the original artwork. Duplicate copies of all material, including illustrations, should be retained by the author. 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