GASTROPODA. 
Fie. 12. 
19 
Cassis madagaseariensis, with cameo engraved upon it. 
Side table-ease B. 
Fie. 13. 
The Common Whelk (Bv.ccinum undatum). 
a, siphon ; b, foot ; c, tentacles ; d, eyes ; e, operculum. 
C 2 
