Uneven Rostrum & Wide Angle Group
Large size OMMASTREPHIDAE

　 RL = 1.5HL, CL<2HL. No pale border between insertion of cutting teeth of rostrum and wing teeth.---
Ornithoteuthis volatilis　
　　

*Beak of Ornithoteuthis volatilis resembles that of small Ciroteuthis calyx by having an apparent fold on the lateral wall and well-marked excavation in the posterior lateral wall beneath the crest. But it can be distinguished from C. calyx by having less developed wing-fold. This beak might be classified into fold-group, but here it is put into Ommastrephids-group as systematic point of view.

　　　RL< 1.5HL, CL>2HL. A narrow and pale border between insertion of cutting teeth of rostrum and wing teeth.---OMMASTREPHIDAE
　　

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