56 TF. H. Hudleston — On the Torkshire Oolites. 



the suture is a double spiral ridge slightly tuberculated, the re- 

 mainder of tlie flat area being marked by finely-granulated spirals. 

 The widest part of the shell is marked by a slight carina with larger 

 granulations, below which are other slight keels : base granulated. 



This specimen represents a young individual : the ornaments are 

 exceptionally well preserved. 



Another specimen. — Same horizon and locality. Bean Collection, 

 British Museum. Figs. 10 and 10a. 



Height 6 '5 millimetres. 



Width 7-75 ,, 



Spiral angle 1 10°. 



This probably represents a more mature individual than the pre- 

 ceding. The body-whorl is slightly bicarinate, the upper keel being 

 somewhat the stronger. The base of the shell is ornamented by 

 fine granulated spirals terminating in a spiral of larger tuberculations, 

 which fringes a moderately wide and deep umbilicus. The aperture 

 is slightly pentagonal, and fairly large. 



Another specimen. — Same horizon and locality. York Museum. 

 Figs. 11, 11a, and 116. 



Height 11-5 millimetres. 



Width 13-25 ,, 



Spiral angle Irregular. 



A fine example of the mature shell. It consists of five whorls : 

 the apical ones are free from granulations, but with the usual carinse : 

 penult sufficiently uncovered to show the lower carina. Suture 

 rather more open than in the smaller specimens. Ornaments of the 

 body-whorl rather coarser than in the smaller specimens. Upper 

 carina bigranulate : lower carina scarcely distinguishable. The 

 tuberculated spiral which fringes the umbilicus very conspicuous 

 (116). Aperture nearly circular, with the pillar lip slightly produced. 



Section B. — Shell sub-conical : bicarination of body-whorl dis- 

 tinct. 



Specimen from the same horizon and locality. My Collection. 

 Not figured. 



Height 12'5 millimetres. 



Width 12-5 „ 



Spiral angle (about) 85°. 



The points in which this form differs from those described under 

 Section A. are (1) the more conical outline of the spire, which is 

 almost acute; (2) the strong bicarination of the body-whorl; (3) 

 the coarser tuberculation of the spiral surrounding the umbilicus ; 

 and (4) the spiral angle of lower value. This specimen has a sort 

 of superficial resemblance to " Trochus " hisertus. 



Another specimen. — Same horizon and locality. Bean Collection, 

 British Museum. Fig. 12. 



Trochiform like the last, the whorls of the spire are devoid of 

 granulations, though the keels are well marked. The ornamentation 

 of the upper part of the body-whorl is peculiar, the spirally granu- 

 late character being masked by an axial or transverse system. Owing 

 to the matrix, it is not easy to say if the lower keel is developed. 



