OMMASTREPHES. 231 



OMMASTREPHES. D'Orbigny. 



Body fleshy, firm, cylindrical, elongated, flanked near 

 its posterior extremity by two triangular fins. Locomotive 

 apparatus formed of " conical perpendicular pits, each 

 communicating by a narrowed groove with a small hori- 

 zontal pit, surrounded by a prominent margin, the whole 

 describing a I'ather prominent triangle, placed at the 

 base of the locomotive tube ; and, besides, of a tubercle 

 prolonged in its upper part into a decreasing nose-shaped 

 crest ; and, lastly, of little horizontal inferior crests placed 

 on the inner margin of the body.*" Eyes very large, 

 opening widely exteriorly, and provided with a lacrymal 

 sinus. Arms ten, like those of Lol'igo. Pen corneous, 

 flexible, elongated, as long as the body, terminating at its 

 lower extremity in a hollow simple cup. 



The cuttle-fishes of this genus closely resemble those 

 belonging to Loligo. Besides the character just given they 

 may generally be distinguished by the short rhomboidal 

 termination of the body formed by the fins combined with 

 the hinder extremity. 



The species are mostly pelagic, and some of them are 

 gregarious. They seem to be distributed all over the 

 world. They are called flying squids by fishermen. 



O. sAGiTTATus, Lauiarck. 



Body elongated ; peduncles of tentacular arms free from 

 suckers ; extremities of their clubs covered with closely-set rows 

 of numerous minute suckers. 



Plate RRR, fig. 1. 



Sepia loligo, Linnaeus, Syst. Nat. Ed. xii. vol. i. p. 1095. — Bruguiere, Enc. 

 Meth. pi. 77, f. 12. 



