881 



White, rather more straightly pyramidal than C. trilineatim, 

 less so than C. terebellum. In both these the ribs are narrower 

 than the interstices, but in C. cereum the reverse is the case. 

 Mr. Hanley's collection, from Australia. 



143. Cerithium assimilatum (pi. clxxxiv. f. 246), C. B. 

 Adams, Shells of Jamaica. 



Cerith. testa nigrescente, C. terebello simili, sed costis sub- 

 tuberculatis ; anfractibus medianis subinllatis, basi subrotundatis. 



A darkly coloured Jamaican shell, like C. triUneatum in form, 

 and showing three ribs on each of the upper whorls, but these are 

 slightly tuberculated. 



1 e. Rather rounded aperture, granulated whorls, short, groove- 

 like canal. — Genus Pirenella, Gray. 



144. Cerithium attramentarium (pi. clxxxv. f. 249, 250), 

 A. Adams. Lampania attramentarium, A. Ad. ined. 



Cerith. testa subpyramidali, nigrescente seu nigro punctata, spi- 

 raliter crebre sulcata; anfractibus prope suturam albis, apicali- 

 bus subplanulatis, medianis gradatim paululum infiatis ; apertura 

 simplici, subovali ; labio interno paululum calloso ; columella tor- 

 tuosa ; canali vix distincto ; labio externo undato. 



In several specimens we have seen, the top whorls are straight, 

 while the lower ones are bulged out a little below, towards the 

 suture ; this may be characteristic, or merely accidental. The 

 shell is pyramidal, typically of a dark colour, although in a variety 

 light and dark spotted. It is spirally grooved, and the outer lip 

 is thin. Mr. Cuming's cabinet. Locality unknown. 



145. Cerithium subviride (pi. clxxxv. f. 247), Nobis. 

 Cerith. testa C. attramentario simili, sed pyramidali, breviuscula, 



sulcis creberrimis, anfractibus haud infiatis, ad suturam nigro 

 fasciatis. 



A single specimen of this species is in Mr. Hanley's collection. 

 It resembles C. attramentaria, but the whorls are more straight, 

 and the upper part of the whorls is marked by a variegated band 

 of dark colour, instead of being white. The specimen figured is 

 Mr. Hanley's. 



146. Cerithium undulatum (pi. clxxxv. f. 248), Nobis. 



Cerith. testa, C. attramentario simili, sed anfractibus ad su- 

 turam nigris, elevatis, undulatim crenulatis. 



It is darkly coloured, elevated, and undulated on the upper 



