OF CONCHOLOGY. 15 



Feelers are those crenated arms, 

 evolved froQi the side of the lepas ana- 

 tifera, and other shells of the second 

 division of lepas. While the animal 

 is in the water it continually moves 

 its feelers, evidently for the purpose 

 of entanglino^ minute marine insects, 

 for food. Plate 1st, fig. 2d, E E. 



BIVALVE. 



Bivalve shells, consist of two parts 

 or valves, connected by a cartilage, 

 and hinge which is generally com- 

 posed of teeth, those of the one valve 

 looking into a cavity in the other. 



The valves of some bivalve shells, 

 are formed exactly alike ; and others, 

 are very different ; the one of some 

 beinor smooth, the other ruo^ose ; one 

 flat, and another convex ; and often 

 one is shorter than the other. 



The shells of the mya, solen, tellina, 

 venus, &c. have in general both valves 

 alike, while those of the spondyluvS, 



