JO C O N C H O L O G Y. 



a progreffive motion, and are for the greater 

 part difficultly, if ever, in our reach ? I 

 repeat, why fhould naturallfls demand of 

 fuch animals only, a iyftem, or arrange- 

 ment, the moft difficult to attain? while 

 all the other orders of animals, whofe ar- 

 rangements hy fuch methods are more 

 eafily attainable, are methodized only, and 

 with univerfal confent, by the obvious 

 charaflers, of teeth, plumage, and fins: 

 charafters that cannot be held in any other 

 light, than as analogous to the external 

 characters, or the Shells of teftaceous 

 animals? 



I am well aware of the arguments al- 



ledged againfl it, vk, that, as long as we 



ftudy only the very ShellSj thofe empty 



habitations, thofe fpoils or remains only 



of the animals, the prefent fole objeds of 



our refearches and coUedions, we confidcr 



thefe beings but partially, or with a fide 



view. There is more to be required. The 



animals that inhabit them fhould certainly 



ffuide 

 t 



