Casanova & Chidgey, 1990
Hooks: 8-10; anterior teeth: 7-18; posterior teeth: 10-20.
Maximum adult body length: 25 mm; tail: 30-40 %.
Body slender; transversal musculature on trunk and tail; head very large; hooks not serrated. Fin bridge absent; one pair of medium length lateral fins both on trunk and tail; lateral fins fully rayed, rounded. Collarette absent; gut diverticula absent; eyes absent. Seminal vesicles conical; position of seminal vesicles: touching neither posterior fins nor tail fin. Ovaries short; ova small. Adhesive papillae and adhesive organs absent. Vestibular organs thick, in juveniles with short papillae; apical gland cell complex present; neck canals absent.
Remarks: 31 specimens from about 1300-3600 m in the Eastern North Atlantic.
Type locality: 49°20.7'N, 12°49.5'W.