CERITHIDEA.— Plate III. 



fractibus suhrotundis, iiUimo infra anijvlalo, slrialo, 

 subcai-inato, varicibus ci-assis, nodiferis ; aperiuru sitb- 

 quadratd, columella retiusculd, canali inco>ispicuo, la- 

 bro crasso, siibreflexo, siniiato. 



The vakicose Cekithidea. Shell solid, pyramidal, 

 brown, wliite-banded, cancellated by spiral, beaded, 

 rather distant ridijes and slightly arched ribs ; whorls 

 rather rounded, the last angular, striated, and subca- 

 rinated beneath, varices thick, nodose ; aperture 

 rather square, columella rather straight, canal ob- 

 scure, outer lip thick, somewhat reflected, sinuous. 



Sowerby; Genera of Shells. 



C Hegicisclni, C. B. Adams. 

 C. Helicoide, C-. B. Adams. 

 C. validum, C. B. Adams. 



Hab. Real Llejos, Central America, at roots of mangroves ; 

 H. Cuming. Jamaica; C. B. Adams. 



The above do not appear to be sufficiently distinct from 

 the well-known form to be regarded otherwise than as 

 varieties. 



Species 20. (Mus. Cuming.) 

 Cerituidea iostoma. Cer. testa solidd, brevi, pyrami- 

 dali, fused, longitudinaliter cosiatd, spiraliter liraid, 

 costis subnodosis ; a>/frac(ibiis subrolundis, ultimo in- 

 fra angulato, striato ; aperturd mibqtmdrafd, labro 

 crnsso, antice subprodticto. 



The ruRPLE - mouthed Cekithidea. Shell solid, 

 sliort, pyramidal, brown, longitudinally ribbed, spi- 

 rally ridged, ribs subnodose ; vvhorls rather round, 

 the last angidated beneath and striated ; aperture 

 rather scpiare, outer lip thick, rather produced in 

 front. 



Pfeiffer. 



Hab. Cuba. 



Much shorter than C. varicosa, with the ribs less dis- 

 tinctly nodose, so that it has much less of a cancellateil 

 and beaded appearance. 



Species 21. 



Cerithidea cornea. Cer. testd tenui, corned, obscure 

 fused, spiraliter tenuistriatd, lonyitudinaliter subdis- 

 tanter costutd, costis lavigatis, subobliquis ; anfracti- 

 bus rectiusculi's, suturd excavatd, ultimo angulato, infra 

 unguium striato, labro tenui expanso. 



The horny Cerithidea. Shell thin, horny, obscurely 

 brown, spirally finely striated, longitudinally rather 

 distantly ribbed, ribs smooth, rather oblique ; whorls 

 rather straight, suture excavated, the last angular, 

 striated below the angle, outer lip thin, expanded. 



A. Adams, Sowerby's Thesaurus, Cerithium, sp. 168. 

 f. 275. 



Hab. Borneo, mouths of rivers. 



