SECTION X- 199 



2, Helices, or Snails that are fiattlfh, 

 and whofe fplres lie, as it were, between 

 Itwo planes or levels. PI. III. fig. 10. 



3* Snails with a fliort or flat turban. 

 (Clavicula breviore.) PL III. fig. 11. 



4. Turbo, or Snails with a produced 

 or lengthened turban. (Clavicula longiore.) 



Pl. III. fig. 1 2. 



5. Cochleas Strombiformes, or Snails 

 whofe turbans are extremely long and 

 flender. (Clavicula tenui & longiiiima.) 

 PI. III. fig. 9. 



I (hall take each of thefe genera fepa- 

 l^ately. And to begin : The firft genus, 

 or Nerits, are Shells whofe mouths are a 

 half circle, the columella or inner lip 

 running diametrically acrofs it in a ftrait 

 line. This lip is very broad or faced, and 

 ^^xtends greatly on the columella. They 



O4 are 



