W. IT. Kudleston — On the Torhshire Oolites. 249 



Shell short, conical, acute, not umbilicated. The spire consists of 

 5 or 6 whorls, which increase with regularity ; outline trochiform and 

 nearly equilateral : sutural excavation wide. Each whorl carries a 

 pair of strong spiral belts (hence probably the name T. hisertus), one in 

 the upper, the other in the lower part: in the upper belt the tubercula- 

 tions are large and wide apart ; in the lower and more prominent 

 belt the tuberculations are much closer, and individually smaller. 

 The space between these two belts forms a wide sulcus, which is 

 sculptured by a system of axial lines in connexion with the tubercu- 

 lations on the belts. Below the anterior of the two belts previously 

 detailed the whorl is much constricted, but rises again to form a third 

 and subordinate belt, which occupies the bottom of the sutural hollow, 

 and is not readily observed in the whorls of the spire. The flanks 

 of the body- whorl are similarly ornamented, but here the third and 

 lowest keel assumes considerable proportions. Base tumid and long, 

 with regular spiral belts closely granulated, and fine axial lines in 

 the sulci. 



The aperture is large and nearly circular, but as the margin is not 

 quite perfect, the point at the extremity of the inner lip is scarcely 

 to be made out. Columella solid. 



Belations and Distribution. — The spire of this sjjecies is so thoroughly 

 trochiform that few would object to Phillips's arrangement in this 

 case. The aperture, at the same time, is so similar to those of the 

 supposed Littorines (Amberleya, " Littorina," etc.), that " TrocJius " 

 hisertus should share their lot, whatever it may be. I have not seen 

 specimens from any of the numerous localities of Inferior Oolite 

 fossils, excepting the Dogger, which could with certainty be referred 

 to Phillips's species. It is true that, in some collections, there are 

 specimens labelled Trochus hisertus, Phil., but some of them have 

 no relationship even generically with the Dogger fossil. This is not 

 to be wondered at, when we bear in mind the nature of Phillips's 

 figure, coupled with the absence of any desci'iption. 



Extremely rare, and confined to the Dogger. 



6Q. — Ambekleya biserta, believed to be a megalomorph of the 

 above. PI. VIII. Figs. 11a, h, c. 



Description. — Specimen from the Dogger (zone 1), Peak (Blue 

 Wyke). Jermyn Street Museum. 



Length restored 32 millimetres. 



Approximate ratio of body-whorl 64 : 100. 



Spiral angle 58°. 



The body-whorl and a portion of the spire alone are preserved ; 

 hence the above measurements are subject to coi'rection. Shell 

 conical, not umbilicated. The spire would pi'obably consist of 6 or 7 

 whorls separated by a very wide sutural hollow. The penult carries 

 2 principal spiral bands ; the upper one is widely tuberculated, and 

 not very prominent, the lower forms a strong keel, and is slightly 

 granulated ; below this the whorl is very much constricted, and 

 terminates in a third subordinate keel above a wide suture. The 

 body-whorl presents these features on a larger scale, with the 



