438 



THE OCEAN WORLD. 



but rarely beyond the point to which the tide reaches. The genus is 

 numerous in species, of which we figure Cerithium fasciatum (Fig. 243) 

 and Cerithium aluco (Fig. 244). The Giant Cerithium, Cerithium 

 giganteum (Fig. 245), is the living analogue of a magnificent fossil 

 species belonging to the Tertiary formation. The single known 

 example of this species belongs to the Delessert Museum at Paris. 

 A manuscript note by Lamarck, attached to this specimen, relates 



Fig. 238. Turrhella Fig. 239. -Turri- Fig. 240. Turritella Fig. 241. Turri- Fig: 242. Turri- 

 replicata (Linnssus). tella angulata sanguinea (Reeve), tella goniostoma. tella terebellata 

 (Sowerby). (Lamarck). 



that this shell was first brought to Dunkirk in 1 8 1 o by an Englishman, 

 one of the crew of an English ship ; he had drawn it up from the 

 bottom of the sea with the sounding-lead from a bed of rocks off 

 the coast of Australia. 



The fourteenth family, Pyramidellidce, contains the genera Eulima, 

 Stylifer, Chemnitzia, and Pyramidella. 



The fifteenth family, Naticida, contains Velutina, Sigaretus, 

 Lamellaria, and Natica ; species of this last being found in most 

 seas. 



The second section of the Prosobranchiata is termed SIPHONO- 

 STOMATA, and is characterised by the shell being spiral and usually 



