ANIMALIA MOLLUSCA. 



103 



prey ; their length and strength make them formidable wea- 

 pons, by whose means it entwines itself around other animals, 

 even destroying men while bathing. 



Genus II. Argonauta. Argonaut. 



No cartilaginous granules on the back ; the pair of feet- 

 nearest the back susceptible of dilatation, at their extremity, 

 into a large membrane; a very thin shell, symmetrically 

 fluted, spirally convoluted, and somewhat the figure of a 

 shallop ; consequently the animal, when the sea is calm, uses 

 it as a boat, employing six of its tentacula as oars, and up- 

 lifting the two, which are spread out as sails. If the sea 

 becomes rough, or an enemy appears, the sails and oars are 

 instantly drawn within the shell, and the shallop sinks. 



Genus III. Sepia. Cuttle-Fish. 



Body contained in a sac bordered throughout its length 

 by a narrow fin, and inclosing in the back a shell formed of 

 an infinity of very small, fine, calcareous laminae ; mouth 

 surrounded with ten arms, of which two are much longer 

 than the rest, and have suckers at the extremity only. 



GASTEROPODA. 



This is a class including a great number of Mollusca of 

 which an idea may be obtained from the Slug and the Snail. 

 Locomotion effected by the aid of a fleshy disk placed under 

 the abdomen ; head more or less distinct and situated anteri- 

 orly, and furnished with very movable appendages {tentacula) 

 placed above the mouth, and which are the seat of touch, 

 perhaps of smell ; eyes very small, sometimes entirely want- 

 ing, sometimes adhering to the head, sometimes fixed at the 

 base, side or point of the tentacula; respiratory organs of 



