883 



in four rows, and rounded. Brought by A. L. Layard, Esq., 

 from Ceylon. 



152. Cerithium clathratum (pi. clxxxv. f. 258), A. Adams 

 (Cerithopsis). 



Cerith. testa alba, ventricosa, subconica; anfractibus biangulatis, 

 angulis tuberculatis, ultimo anfractu carinato; apertura rotun- 

 data. 



A beautiful white species, brought by Mr. Cuming from 

 Baclayon, Island of Bohol, Philippines. It is conical, and has 

 the whorls ventricose, with two tuberculated angles. The last 

 whorl has a keel. 



Division 2. — Frequenting marshes or rivers ; canal not pro- 

 dticed ; opercuhim round, with many whorls. — Potamides, 

 Brongniart. 



2 a. Aperture sinwons, emarginated at the base, columella cal- 

 lous. — Genus Pyrazus, Montf. 



153. Cerithium palustre (pi. clxxxv. f. 261), Linnaus 

 (Strombus), Linn. Syst. Nat. ed. 12. p. 1213 ; Brug. Diet. C. 

 crassum, Lamk. no. 15. 



Cerith. testa magna, crassa, pyramidali, fusca-nigrescente arcua- 

 tim costata, spiraliter inciso-sulcata, inter sulcos planulata ; anfrac- 

 tibus subplanulatis, ultimo anfractu univaricoso; apertura sub- 

 ovali ; labio interno brevi subcalloso, labio externo expanso sub- 

 denticulato, superne sinuato ; canali circulari, brevissimo. 



The very large, darkly coloured, sulcated species, with rather 

 expanded and curved outer lip. Hab. Marshes and mouths of 

 rivers in the Red Sea and East Indies. There is a variety found 

 at the mouths of Australian rivers, with short white whorls and 

 fewer sulci. 



154. Cerithium sulcatum (pi. clxxxv. f. 262), Born (Mu- 

 rex sulcatus), Mus. p. 320. Murex Molluccanus, Gmel., p. 3593. 

 C. sulcatum, Brug. Strombus mangiorum, Schrmt., Phys. Conch, 

 p. 383. N. fuscus, Gmel. 



Cerith. testa ventricosa, brevi, pupgeformi, longitudinaliter pli- 

 cata, spiraliter sulcata, fusca; apertura auriformi; labio externo 

 crasso, ad^ columellam trans canalem incurvo ; canali separato, 

 rotundo. 



A thick, pupiform, sidcated species, in which the outer lip is 



