Lönnberg, 1898
Mantle narrow, adult width 20-25% ML. Head in larvae can be wholly (including arms) retracted into mantle. Fins petaloid in larvae, transverse-oval in juveniles, heart-shaped with tapering tail in adults. Arms rather short, in adults approx. 25% ML. Arm suckers transformed into hooks at ML approx. 25 mm. Nine to ten transverse rows of suckers on basal halves of 4th arms. Tentacular club rather short, in adults approx. 15-24% ML, moderately wide. In adults central part with one large central, one smaller distal, and 3-5 small proximal hooks, surrounded by naked space; 4 rows of small suckers on dactylus and on ventral side of central part, 2-4 on dorsal side. Fixing apparatus represented by short strong transverse ribs (each with 1 sucker), and grooves. In larvae whole tentacular stem with 4 rows of suckers, zone of growth occupying distal half of larval club. At ML approx. 15-20 mm, 2 large buds appear in central part club, later transformed into hooks. Central, distal, and proximal hooks developed at ML approx. 20-25, 25-30 and >30 mm, respectively. Gladius narrowly lancet-shaped, with two widenings. Radula with 5 longitudinal rows of teeth. No photophores. Egg size supposedly about 5 mm. Larvae distinguishable by thin mantle with sparse, large chromatophores, and by large spindle-shaped midgut gland; juveniles by club structure. ML up to 35 cm.
Only one species in the South Atlantic. Larvae in some places very common in the upper layers.