|Abstract||Three eel families, the Simenchelyidae, Synaphobranchidae and Dysommidae, currently recognized by most authors, are reduced to subfamilies of the Synaphobranchidae [SIMENCHELYINAE, SYNAPHOBRANCHINAE, DYSOMMINAE] with 9 genera and an estimated 30 spp. One new species each of Dysomma [D. goslinei ] and Ilyophis [I. arx ] and a new genus and species, HAPTENCHELYS texis, are described. The study of these new taxa and of the newly discovered Meadia abyssalis required reassessment of genera and realignment of genera within the expanded family. The scaleless Haptenchelys belongs with the otherwise scaled Synaphobranchinae, and Ilyophis, formerly with 1 scaled sp. and aligned with Synaphobranchus, is shown to contain both naked and scaled species and to belong to the Dysomminae, which until now contained only naked species. The subfamilies are redefined. Larvae representative of a spectrum of lineages within the family are unique among eels in having telescopic eyes. The Synaphobranchidae, sole family of the superfamily Synaphobranchoidea, is considered to be one of the more primitive eel groups and structural modifications between the living genera are great compared to those of more speciose tropical coastal eels. Keys are provided to the genera and species except for the species of Synaphobranchus.