SECTION V. 



f 01 



SECTION V. 



S the feveral fyftems of amhors are 

 /"^ fet forth, I fhali gradually proceed 

 on my method or arrangement : however, 

 I will not open the whole at one view, 

 it being my defign to detail the feveral 

 families as I progreffively treat on them. 



But, before 1 begin, it is abfolutely ne- 

 ceflary to fix fome eflential or flandard 

 charafters to all Shells ; by which they 

 can be divided into families or claffes, 

 genera and fpecies. Thefe charaders muft 

 always be formed froni the chief parts of 

 the Shells, the differences of which, in 

 Ihape, fize, lituation, or other marks or 

 particularities, will enable us to form re- 

 fpeftive families orclafles, and thofe farni- 

 lic3 into genera, and afterwards into fpecies, 

 by other fubordlnate charaflers. Thus in 



H 3 Univalves, 



