132 

 CLASS VII. CEPHALOPODA. 



(CUTTLES.) 



THE Cuttles and Squids, of which we have but 

 a few species on our shores, are MOLLUSCA, which 

 make the nearest approach of all Invertebrate 

 animals to the Vertebrate forms. Their most 

 characteristic peculiarity is, that the front of the 

 body, which forms a large, well-marked head, 

 carries numerous fleshy arms, which are effective 

 instruments for the seizing and holding of the 

 living prey on which the animals feed, and are 

 also used for the purpose of crawling. 



Each arm is furnished along its inner side with 

 a single or double series of sucking-cups, each of 

 which, on being affixed by the animal to any 

 surface, adheres with a force so great, that it is 

 easier to tear apart the limb than to cause the 

 sucker to let go its hold. The suckers are short 

 cylindrical or conical warts, with a central hollow, 

 filled by a moveable fleshy piston, which can be 

 withdrawn at the animal's pleasure, forming a 

 vacuum, when the edges of the cavity, pressed by 

 the whole weight of the overlying water, and 

 with that of the atmosphere above it, adhere to 

 the body of the victim, with a force dependent on 

 the muscular power employed to retract the piston. 



In one Family there is, in addition to the ordinary 

 arms, a pair of long and slender tentacles, which 

 are dilated at their extremities, where they carry 

 groups of suckers, similar to those of the arms. 



In the midst of the area surrounded by the bases 



