454 THE OCEAN WORLD. 
branchial cavity. The foot is large, and furnished with a horny 
operculum. ; 
These animals keep near the shore, in shallow water: They walk 
Mt ge fl 
Fig. 279.—Cassis glauca Fig. 280.—Cassis rufa Fig. 281.— Cassis canaliculata 
(a jnnseus). (Linnzus). (Brugiéres). . 
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. 
