438 



THE OCEAN WORLD. 



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

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

 and Cerithium aluco (Fig. 244). The Giant Cerithium, Cey-ithinm 

 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 



§^ 



KU'^ 



Kig. 238. — Turritella Fig. 239.— Tiirri- Fig. 240. — Turritella Fig. 241. — Turri- Fig. 242. — Turri- 

 replicata (Linnaeus). tella angulata sangiiinea (Reeve), tella goniostoma. tella terebellata 

 (Sowerby). (Lamarck). 



that this shell was first brought to Dunkirk in iSiobyan 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, PyramidellidcB^ contains the genera Eulima, 

 Stylifer, Chemnitzia, and Pyrajuidella. 



The fifteenth family, Naticidts, contains Velutitia, Sigarctus, 

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

 seas. 



The second section of the Pi-osobranchiata is termed Siphono- 

 .STOMATA, and is characterised by tlie shell being spiral and usually 



