344 HABITS OF CEPHALOPODS. 



956. The animals of this Class are extremely voracious in 

 their habits ; and seldom, if ever, devour anything but animal 

 food. They chiefly prey upon small Fishes and Crustacea ; and 

 seem especially destined to restrain the too rapid multiplication 

 of the latter. Winding its arms around the body and limbs of 

 even a powerful Crab, and securing them all by fixing its suckers 

 upon their surfaces, the Cuttle-fish can pick the shell to pieces 

 with its powerful mandibles, and extract the contained flesh, 

 without fear of injury; an action which no animal of any 

 other Class could attempt. The firm armour, and powerful 

 crushing jaws, of the more ancient Fishes, might have enabled 

 them likewise to feed upon Crustacea; but no such Fishes now 

 exist. The Common Cuttle-fish, and the Calamaries or Squids, 

 are often very troublesome to fishermen, by following shoals of 

 fish into the nets, devouring large quantities of them, and 'watch- 

 ing an opportunity to dart away before they can themselves be 

 seized. In their turn, they become the prey of the larger Fish 

 and of Cetacea. They are much used as baits in the Newfound- 

 land Cod Fishery ; and in the stomachs of the smaller Cetacea 

 great numbers of the undigested horny Mandibles are frequently 

 found, indicating (of course) that at least a corresponding num- 

 ber of the Cuttle-fish have been devoured by them. Some 

 species of this class attain a considerable size. The Onychoteuthis, 

 the suckers on whose two long arms are furnished with hooks at 

 their edges, has been known to attain the length of six feet ; and 

 it is much dreaded by the natives of the Polynesian islands, who 

 are said to have been attacked by it, when diving for shell-fish. 



957. The Class of Cephalopoda may be divided into two 

 Orders, according to the number of the gills ( 950); the 

 DIBRANCHIATA, or two-ffilled, including the Cuttle-fish, Argo- 

 naut, and their allies, having only one pair of those organs ; 

 and the TETRABRANCHIATA, or four-gilled, including only the 

 true Nautilus among the existing Cephalopods, but comprehend- 

 ing a vast number of species now extinct, possessing four of 

 those organs. The latter of these Orders is the one most allied 

 to the Gasteropoda, both in the structure of the shell, and in the 

 conformation of the animal. 



