XVIII. 
CHARACTERISTIC DEEP-SEA TYPES.— MOLLUSKS. 
CEPHALOPODS. 
Tue 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. 3. (Verrill.) 
which they have been obtained. Many of them are pelagic, and 
serve as food for a large number of marine animals.’ 
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. 
