S E C T I O N VI. 133 



every fyftem or method ; which principles 

 or characters fhould always be taken from 

 die chief part of the objedls, and not from 

 feveral parts. This chara6ler fhould alfo 

 be the conftant one through the whole 

 iyftem, to preferve a perfeft regularity. 

 Thus all bodies which agree in one fixed 

 charader form the clafs, and the affinities 

 or differences of thofe bodies to each other 

 in other lefs chief or principal parts, create 

 the fubordinate genera and fpecies. 



On this maxim I fhall build my fyftem, 

 nnd for all the turbinated Univalves, I fhall 

 fix on the aperture or mouth of the Shell 

 as the head or chief characler. For the 

 Bivalves on the hinges, and for the Mul- 

 tiyalves, on the number of valves. 



The fimple figure, the.chambered flruc- 

 ture, and the latent whirls of the revolved 

 Shells, which are all the remaining Uni- 

 valves that are not charafterifed by the 

 mouth, fuch as the Limpets, Ammonia, and 

 K 3 Cowriesji 



