253 



angular appearance to the lower surface of the shell. 

 They are marine, and the animal has the faculty of bu- 

 rying itself in the sandy bottom of the sea. 



Spire of the Shells having thickened bands. 



Cassis Madagascariensis Cassis crumena 

 cornuta plicaria 



tuberosa 



areola 



flammea 



zebra 



fasciata 



decussata 



glauca 



abbreviata. 



Spire without bands. 



Cassis rufa 



Cassis sulcosa 



pennata 



granulosa 



testiculus 



saburon 



achatina 



canaliculata 



pyrum 



• • • • • semigranosa 



Zeylanica 



vibex 



Cassis 



erinaceus. 



[And one 



fossil species.] 



