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 perfect. 

 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 occasional 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 perfect. Ccrith. ladeim, 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. Nj^st, must of course remain only as a synonyme. 



3. Cerithium trilineatum. Phil. Tab. VIII, fig. 4, 4 «.* 



Ceuithium trilineatum. Phil. Enum. Moll. Sic. vol. i, p. 195, t. 11, fig. 13, 183fi. 



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



— S. Wood. Catalogue 1842. 



C. Testa minutd, turritd, stibulatd ; apice ohtuso, costato, et cancellato ; anfractihus pla- 

 )iiuscidis, cingulos ires ohfnsos ferentihns ; intersfltiis Jonr/itiidinaUter sfriatis ; cnnnli brevi. 



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

 rather flat, ornamented, with three transverse obtuse ridges, having longitudinal 

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



Axis, I 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 interspaces, 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 costae, 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 theyegg. 



4. Cerithium tuberculare. Mont. Tab. VIII, fig. 5, a — c. 



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



5 a. Magnified portion. 



5 h, var. subulatum. 



5 c, var. nanum. 

 MuREX TUBERCULARis. Mont. Test. Brit. p. 2/0, 1803. 

 Cerithium pygm.ijum (?). Phil. En. Moll. Sic. t. 25, fig. 26, 1844. 



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



— TUBERCULARE. S. Wood. Catalogue 1842. 



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



