STOMACH OF MOLLUSCA. 



h, mouth of lanthina ; c, the same 

 opened and enlarged, a, tongue. 



are horny, or furnished with teeth. Such as are carni- 

 vorous, have commonly a fleshy pliable tube, which can 

 be protruded or drawn in at pleasure, with a round 

 opening at the end, edged 

 by a strong substance, 

 and armed with littl® 

 teeth. Various means 

 are also possessed for 

 brinoring- their food to 

 the mouth ; sometimes 

 this proboscis is stretched 

 out, and at others it pierces the shells of other moUusca, 

 that it may suck out the flesh of the inhabitants. They 

 are, moreover, provided with tentacula, a word de- 

 rived from the Latin tentare, to try, or feel, denoting 

 parts acting like those projections of the snail called 

 horns, with which the little animal tries and feels 

 about ; they vary in number, 

 and have muscles and nerves. 

 There are also instances in 

 which the lips of the pro- 

 boscis are furnished with 

 spinous cilia. 



The stomach of some is 

 simple, of others complex. 



Cilia of Buccinum undatum. 



