70 MOLLUSCA FROM THE CRAG. 



Axis, \ an inch. 



Locality. Red Crag, Walton Naze. 



Of this species I have but three or four specimens, and those are not quite per- 

 fect. It is presumed to be the same as the Belgian species, though the aperture in 

 the figure referred to above is very unlike that of our shell, and is probably not 

 well represented. It appears to differ from C. lima, Brug., in not having the occa- 

 sional obtuse varices of that shell, and the volutions are not so flat as in that 

 species. The base of my specimen is smooth, but perhaps it is not so when per- 

 fect. Cerith. lacteum, Phil., is described as having but three rows of granules ; our 

 shell has four, and they are very distinct. 



The name in my Catalogue being without description, though prior to that of 

 M. Nyst, must of course remain only as a synonyme. 



3. Ceeithium tetlineatum. Phil. Tab. VIII, fig. 4, 4«.* 



Cerithiuh trilineatum. Phil, Enum. Moll. Sic. vol. i, p. 195, t. 11, fig. 13, 1836. 



— Bujard. Mem. de la Soc. Geol. de France, p. 289, 1837. 



— S. Wood. Catalogue 1842. 



C. Testa minutd, turritd, subulatd ; apice obtuso, costato, et cancellato ; anfractibus 

 planiusculis, cingulos tres obtusos ferenlibus ; ijiterstitiislongitudinaliter striatis ; canali brevi. 



Shell small, turreted, and tapering, with an obtuse apex ; volutions numerous, 

 and rather flat, ornamented, with three transverse obtuse ridges, having longitu- 

 dinal striae between them ; aperture subquadrate ; canal short and inflected. 



Avis, f of an inch. 



Locality. Cor. Crag, Sutton. Recent, Mediterranean. 



Imperfect specimens of this species are by no means rare. The shell is thin 

 and fragile. It is peculiarly distinguished by three transverse bands or 

 ridges not quite so broad as the spaces between them : these are obtuse or rather 

 flat upon the top, with longitudinal striae or visible lines of growth in the inter- 

 spaces, and there is a smaller ridge at the base of the volution, below which it is 

 smooth. The apex is very obtuse. The first volution is distinctly marked with 

 numerous longitudinal costas, but is without the transverse ridges, while on the 

 second it is strongly cancellated, being probably the peculiar markings of the young 

 shell previous to its exclusion from the egg. 



4. Ceeithium ttjbeeculaee. Mont. Tab. VIII, fig. 5, a — c. 



Fig. 5, var. vulgaris. S. Wood. 

 5 a, Magnified portion. 

 5 b, var. subdlatum. 

 5 c, var. nanum. 

 Murex tubercularis. Mont. Test. Brit. p. 270, 1803. 

 Cerithium pygm^um (?). Phil. En. Moll. Sic. t. 25, fig. 2G, 184-1. 



Henckklh. Nyst. Coq. foss. de Belg. p. 340, pi. 41, fig. 12, 1844. 



— tuberculare. £. Wood. Catalogue 1842. 



* Fig. 4 a is a highly magnified representation of the apex. 



