454 



THE OCEAN WORLD. 



branchial cavity. The foot is large, and furnished with a horny 

 opercukim. 



These animals keep near the shore, in shallow water. They walk 



P"ig. 279. — Cassis glauca 

 (Liniiieus). 



Fig. 280. — Cassis rufa Kig. 281.— Cassis canaliculata 



(ljinna;us). (Brugieres). 



Figs. 282 and 283.— Cassis Madagascariensis (Lamarck\ 



slowly, and often sink themselves into the sand, where they prey 

 upon small bivalves. There are not very many species ; but speci- 

 mens from the Indian Ocean are often large and beautifully marked. 



