OF CONCHOLOGY. 15 



Feelers are those crenated arms, 

 evolved from 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 entangling 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 

 being; smooth, the Other rugose ; 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 spondylus, 



