XVIII. 



CHARACTERISTIC DEEP-SEA TYPES. MOLLUSKS. 

 CEPHALOPODS. 



THE shoal-water species of cephalopods, the squids and cuttle- 

 fishes, live upon the bottom ; but, being powerful swimmers, 

 they are capable of extensive migration, so that with them as 

 with fishes it will always be difficult to ascertain the depth from 



Fig. 274. Opisthoteuthis Agassizii. Abt. |. (Verrill.) 



which they have been obtained. Many of them are pelagic, and 

 serve as food for a large number of marine animals. 1 



Professor Verrill, who has examined the cephalopods collected 

 by the " Blake," mentions as specially noteworthy the follow- 

 ing: Opisthoteuthis Agassizii (Fig. 274), a species with a 

 broad body of a dark chocolate color, long fins, and arms united 



1 Very common in the Gulf Stream is surface. It is known as the " flying 

 the Sthenoteuthis Bartrami, large speci- squid," often darting out of the water in 

 mens of which are often caught on the the velocity of its movements. 



