The Moon Snail 



43 



of smaller creatures. But in the case of the majority, 

 the finish will he In the stomachs of the selfsame 

 mussels which serve as prey for the full-grown moon 

 snail. 



Now, to a certain extent, the two mollusks which I 

 have here reviewed, the mussel and the moon snail, 

 may be taken as representative of their classes. That 

 Is to say, the one Is largely typical of the bivalves, or 



FREE-SWIMMING LARV^ OF THE MOON SNAIL. (gRE.\TLY ENLARGED.) 



pelecypods ; the other Is an example of the univalves, 

 or gastropods. It Is to be noted, however, that the 

 habits of the various species within each class may 

 differ considerably. For Instance, not all pelecypods 

 lead a stationary life; neither do all gastropods live 

 by preying. 



The pelecypod mollusks are. In fact, a very extensive 

 group of animals which vary widely even In their struc- 

 ture. It is to this group that also belong the clam, the 



