46 CATALOGUE OF CEPHALOPODA. 



Synopsis of Genera. 

 A. Tentacular and sessile Arms vjith claw-like Hooks. 



1. Enoploteuthis. — Fins subtermlnal, dorsal, rhombic. Sessile 



arms with hook only. Shell pennate, lanceolate. 



2. Ancistrocheirus. — Fins occupying the whole side of the back, 



rhombic. Sessile arms with hooks only. Shell dilated at each 

 end. 



3. Abralia. — Fins subterminal. Sessile arms with hooks at the 



base and cups at the tip. Shell lanceolate, concave on the 

 edges. 



4. OcTOPODOTEUTHis. — Fins on the hind part of the back, roundish. 



Shell narrow. 



5. AcANTHOTEUTHis. — Fins ? Shell narrow, gra- 



dually dilated above. 



B. Tentacular Arms with Hooks. Sessile Arms with Cups and 



Rings. 



6. Onychoteuthis. — Club of tentacular arm with hooks. Shell 



lanceolate, pennate, sides thin. 



7. Ancistroteuthis. — Club of tentacular arm with hooks only. 



Shell narrow, rather dilated in front, with one central and 

 two marginal ribs. 



8. Onychia. — Club of tentacular arm with hooks on the centre, 



and with two rows of small cups on each side. Shell lanceolate, 

 pennate. 



C. Tentacular and sessile Arms with Cups and horny Rings. 



9. Ommastrephes. — Fins rhombic, posterior, caudal. Internal 



cartilage of mantle dilated below. Shell narrow, dilated in 

 front with one central and two marginal ribs. 



A. Tentacular and sessile Arms furnished with Hooks. 



1. ENOPLOTEUTHIS. 



Body elongate, with regular longitudinal lines of minute tubercles 

 beneath ; sometimes produced into a more or less elongate acute 

 tail. Fins angular, on the hinder part of the back; together 

 rhombic. — Head rather large, subcylindi'ical. Buccal mem- 

 brane eight-lobed ; two upper bands distinct, and inserted 

 between the two dorsal arms. — Sessile ar?ns with a series of 

 closed horny claw-like hooks, enlarged at their base, and 



