Aphyonus, g. n. Ophidiid.

Head, body, and tapering tail strongly compressed, enveloped in a thin, scaleless, loose skin. Vent far behind the pectoral. Snout swollen, projecting beyond the mouth, which is wide. No teeth in the upper jaw; small conical teeth in the lower, pluriserial in front and uniserial on the side. Vomer with a few rudimentary teeth; palatine teeth. Nostrils close together, small. No externally visible eye. Barbel none. Ventrals reduced to simple filaments, placed close together and near to the humeral symphysis. Gill-membranes not united. Four branchial arches, the posterior without gill-laminse; the anterior with very short gill-rakers and with rather short gill-laminae. Head covered with a system of wide muciferous channels and sinuses, the dermal bones being almost membranaceous, whilst the others are in a semicartilaginous condition. Notochord persistent, but with a superficial indication of the vertebral segments (as in some Leptocephaline forms).