Joubin, 1919
Mantle sac-like in larvae, cup-like in juveniles, narrow cup-like, tapering into thin tail in adults. Head wider than mantle, eyes in larvae and juveniles on short stalks, protruding. Fins in larvae petaloid, in juveniles transversely-oval, located on posterior mantle end, in adults widely transverse-oval, located in mid-mantle, fins do not join dorsally. Fin length 60-80% ML. Arms long, tentacles very long. Widened club with prominent aboral keel. Central suckers in mid-part of club very large in larvae but not larger than marginal ones in juveniles and adults. Funnel cartilage of characteristic form with one deep central pit from which two grooves extend, one wide anterior and a narrow posterior. Mantle cartilage is an L-like crest with knob on summit. Gladius lancet-like with long acute end conus. A large photophore on ink sac, noticeable in early juveniles, and a series of 15-20 small ones, of different form and size, on eye iris (only in adults). No photophores on body surface. Larvae may be distinguished by protruding eyes and large central club suckers. ML up to 60 cm.
Another species, Cycloteuthis akimushkini Filippova, 1968, with narrow retractable head and fin length approx. 50% ML, was reported from the subtropical South Atlantic. Juveniles undescribed.