108 J. Starhie Gardner — Cretaceous Gasteropoda. 



It was first described by d'Orbigny in the Pal Frang. Terr. Cret. 

 (p. 50, pi. 154, figs. 1 to 3). Although of much larger dimensions 

 than the shell originally described by d'Orb., the spiral angle, the 

 number and appearance of the ribs, and a slight depression under 

 the basal keel, named by him the canal, are points of resemblance 

 that cannot be mistaken. 



The specimen figured and the other above referred ta are from the 

 Cracker rocks of Atherfield, Isle of Wight, and are in the Geological 

 Museum, Jermyn Street. The smaller specimen, Fig. 6, was found 

 by Mr. Meyer at the base of the Folkestone beds, Shanklin. 



So. ischyra\ J. S. G. Lower Greensand. Plate III. Fig. 7. 



Shell elongated, angle about 24° ; whorls numerous, irregularly 

 inflated, those near the apex being most elongated ; ribs twelve or 

 thirteen, rounded, coarse, irregular, sometimes nodose and flexuous ; 

 strise raised and very even, with the intervals distinctly transversely 

 ribbed ; sutures distinct and keeled, the keel becoming visible as 

 usual upon the last whorl in the form of a rounded collar ; columellar 

 region marked with numerous lines of growth ;. mouth ovate. Cast 

 smooth with slightly marked ribs. 



From the Lower Greensand of Shanklin, described from an unique 

 specimen in the British Museum. 



So. Cruoiana,^ Pict. & Camp. Neocomian. Plate III. Figs. 8, 9. 



Shell elongated, angle 18°, whorls inflated and rounded; ribs 

 twelve to fourteen, oblique, obtuse, extending to the sutures, more 

 salient and fewer on the smaller whorls ]. striae numerous and fine ; 

 sutures distinct ; last whorl keeled, basal region smooth ; mouth 

 ovate. 



Figured and described by Pict. &r Camp., Terr. Cret. de Ste.-Croix, 

 pi. Ixxii. figs. 8, 9. The umbilical region, as described by them, 

 p. 329, appears to be strongly striated, and to be marked with lines 

 of growth ; the smoothness of our specimens may, however, be the 

 result of less perfect preservation. The ribs are also slightly more 

 oblique than is represented by Pictet and Campiche. 



The specimens figured are from the collection of Mr. Meyer, and 

 were obtained by him in the Lower Greensand of East Shalford. 



So. FiTTONi, J. S. G. Upper Greensand, Blackdown. 

 Plate III. Figs. 10, 11. 



Shell elongated, angle 20° to 26° ; whorls seven to nine, more or 

 less inflated ; ribs twelve to fourteen, rather coarse, prominent and 

 rounded ; staige numerous, regula,r, well defined, with narrow inter- 

 vals (Figs. lOct, 10c) sometimes alternately preponderating (Fig. 10&) ; 

 mouth ovate or rounded. The last whorl is keeled, but not so 

 strongly as in the other species now described ; the keel is crossed 

 by the ribs near the columella ; the basal region is strongly striated. 



This is the most abundant of the Seal arise met with at Blackdown, 

 and I have therefore been able to examine a rather large series of 



^ i<Txi>pos, strong. 2 gte. -Croix, Sancta Crucis. 



