Keys are offered for identifying all of the taxa currently recognized in the family Oplophoridae, including three new monotypic genera: Heterogenys for Acanthephyra microphthalma, Janicella for Oplophorus spinicauda, and Kemphyra for Notostomus corallinus. Of the 27 species remaining in the genus Acanthephyra, 14 are now known from the Philippine-Indonesian region. One new species is proposed in the genus Ephyrina; E. childressi was collected in the Halmahera Sea by the Alpha Helix in 1975, bringing to six the number of species recognized in that genus; two of the three species encountered in the Philippine-Indonesian region—E. figueirai and E. ombango—were originally described from the eastern Atlantic. Four species are currently recognized in the genus Hymenodora, but none of them have been definitely recorded from the Philippines or Indonesia. Five species are represented in the genus Meningodora, but some doubt is expressed about the inclusion of other than the type-species, M. mollis. The eight species recognized in the genus Notostomus are distinguished in a distinctly provisional key. Four species remain in the genus Oplophorus after the removal of O. spinicauda. All five species currently known in the genus Systellaspis are recorded from the Philippine-Indonesian region. Illustrations are offered of as many oplophorid species as possible, especially of the mandibles, first and second maxillipeds, endopods of the first male pleopods, and the appendices internae and masculinae, all of which proved to be variably significant as diagnostic generic and/or specific characters. Seven species are covered in a key to the Philippine-Indonesian species of the genus Nematocarcinus, including a new species, N. bituberculatus from Lagonoy Gulf, southeastern Luzon, and off the west coast of Halmahera.