(Family):Outermost pelvic and some of uppermost and lowermost pectoral or outermost pelvic or lower caudal rays prolonged. Eye minute, laterally directed. (Genus):Pectoral fin bifurcated, the uppermost ray prolonged. The lowermost pelvic ray prolonged, extending beyond origin of anal fin. The lowermost pelvic ray prolonged. Outer pelvic and lower caudal rays never longer than SL. Adipose fin present. (Species):Uppermost pectoral ray not notably thicken at its base. All rays of upper part of pectoral fin well developed. Fewer than 6 rays in lower part of pectoral fin. Outermost pelvic ray extending at least beyond caudal penduncle. Pelvic and lower caudal rays prolonged. Subcaudal notch absent.
Distribution:
Most, living in bathypelagic region, have been taken from the tropical to temperate waters in western Atlantic.
Remarks:
This species differs from member of the genus with uppermost pectoral ray not notably thicker at its base, fewer than 6 rays in lower part of pectoral fin, subcaudal notch absent. (Miyake and Aizawa)