10 THE ELEMETsTS 



It is upon the exclusive sliape of 

 the shell, and not the aniraal-inhabi- 

 tant, that the arrangement of Concho- 

 logy is formed. 



In early periods, naturalists were 

 in much doubt whether to construct 

 the arrangement from the animal, or 

 the shells ; and at last it was deter- 

 mined, for the best of reasons, that it 

 should be the latter. Of the great 

 quantities of shells found, how few 

 have had the animal in them ? indeed, 

 there are hundreds we shall never be 

 able to ascertain. The greater part 

 of shells in collections, have been 

 found upoii the beach, without the 

 animal in them, which have been cast 

 ashore by the agitation of the sea in 

 storms, &c. 



Most shells are very different in 

 their young and adult state, both in 

 form and colour ; the student ought, 

 therefore, to make himself well ac- 

 quainted with the generic characters, 



