J. Starkie Gardner — Cretaceous Gasteropoda. 109 



specimens, and have arrived at the conclusion that notwithstanding 

 the varying convexity of the whorls and number of ribs in different 

 shells, all the more coarsely-ribbed and striated forms met with in 

 these rocks are referable to a single species which has hitherto been 

 confounded with SiC. Dupiniana. It may, however, readily be dis- 

 tinguished by its lesser angle and higher whorls, by the closer 

 arrangement of the • ribs, finer striae, and striated apical whorls. It 

 is a much smaller and more delicate shell. 



The original from which Fig. 10 is taken is in the British Museum, 

 and Fig. 11 in the Museum of the Geological Survey, Jermyn Street. 



So. CLiMASPiRA,^ J. S. Gr. Upper Greensand, Blackdown. 

 Plate III. Figs. 12 and 13. 



Shell elongated and very delicately tapering, angle 25° ; whorls 

 eleven, convex and inflated ; ribs fifteen, very narrow, salient and 

 shar^jly defined ; striae numerous, fine, distinct (Fig. 12a). The last 

 whorl possesses g, spiral keel, the basal region is well marked, being 

 apparently thickened over and filling in the ribs, and is beautifully 

 reticulated by transverse and spiral lines. The principal transverse 

 lines are coincident with the ribs ; the thickening of the basal region 

 must have occurred after the ribs were formed, obliterating them 

 and leaving only indications of the lines of growth visible. Aper- 

 ture rounded. 



This is the most beautiful and delicate of all the fossil Cretaceous 

 Scalarige. The number and sharpness of the ribs and convexity of the 

 whorls are its distinguishing characters. Fig. 12 was formerly in 

 the collection of Dr. Bowerbank, and is now in the British Museum. 

 Fig. 13 is in the Bristol Museum. 



So. PULCHRA, Sby. Upper Greensand, Blackdown. PL III. Fig. 14. 



Shell very elongated and tapering; angle 12°; whorls twelve, mode- 

 rately high and convex ; ribs eleven, distinct, prominent, rounded ; 

 striae very fine and regular ; basal keel not very distinct, and crossed 

 by the rilDS ; the umbilical region is thickened and somewhat raised, 

 in the manner described in the last species. Mouth pear-shaped. 



This shell is briefly described and figured by Sowerby in the 

 Trans. Geol. Soc. vol. x. 2nd ser. p. 343, and is not unlike Sc. 

 gracilis, recent, but it also bears a strong resemblance to some of the 

 Chemnitzice, especially in the form of the mouth. It is the most 

 slender of all the Cretaceous Scalidce. The crossing of the basal keel 

 by the ribs is also an interesting feature. 



The original specimen I believe to be unique, and I am indebted 

 to the kindness of Mr. Tawney, F.G.S., of the Bristol Museum, for 

 the opportunity of examining it. 



So. CERiTHioiDES, J. S. G. Lowcr Greensand. PI. III. Fig. 16. 



Shell elongated, angle 21^ ; whorls numerous, inflated, depressed, 

 but becoming more elevated near the apex ; ribs thirteen or fourteen, 

 prominent, blunt and irregular, intercostal spaces ill-defined ; striae 



^ kATukI, a ladder. 



