FIG. 97. 



B C 



E 



F 



Various forms of Gasteropodous Shells : 



A, Patella; B, Dentalium; C, Pileopsis ; D, Helix; E, Achatina; F, Siga- 

 rctus; G, Vermetus; H, Scalaria; I, Nerinea; K, Murex; L, Valuta. 



