TF. S. Hudleston — On the Torkshire Oolites. 245 



the line. If we call Figure 3 Turho PJiilUpsii, and Figure 4 Littorina 

 muricata, as was done by Mr. Leckenby, we shall put a double 

 accent on differences, never perhaps very great, though somewhat 

 increased by conditions of preservation in a different matrix. Any 

 one tabulating this kind of nomenclature would record two forms 

 practically identical, not only as differing specifically, but also 

 generically. In this fashion the Kelloway rock of Scarborough 

 would be credited with Turho PhUlipsii, and the Oxford Clay with 

 Littorina muricata, and thus would be created a gap in the Geological 

 Eecord, which had no existence except in an imperfect system of 

 nomenclature. 



Doubtless many such gaps have had a similar origin. 



52. — ^Amberleya armigeka, Lycett, 1863. Plate YIII. Figs. 5a, 56. 



1863. Amberleya armigera, Lycett, Suppl. Great OoL Moll. p. 20, pi. 31, fig. 6. 



1866. Turbo armigera, Lycett, Leek. Cat. of Cornbrash Fossils. 



1875. Amberleya armigera, "L. aud M." Phillips, G. T. 3rd edition, p. 258. 



Bibliography, etc. — This is pi'obably the Piirpurina ornata of 

 Dr. Wright's Cornbrash List (vol. cit. p. 27), and is most likely the 

 Littorina ornata of Brauns (Mitt. Jura, p. 177), from the beds of 

 Ostrea Knorrii. 



Description. — Specimens from the Cornbrash (zone 4), Scar- 

 borough. Leckenby Collection. 



Length 30 millimetres. 



Width of last whorl to length of shell 55 : 100. 



Spiral angle 55°. 



Shell conical, pointed, eucycloid ; outline of spire oblique, sutures 

 wide, almost gaping, especially as between the body-whorl and 

 the rest of the spire. Whorls about 7 : those posterior to the 

 penult carry three spiral bands, somewhat widely nodular, the 

 nodules being more or less connected by axial lines across the sulci. 

 The penult shows four spirals, the second being very subsidiary : 

 the two lowest spirals form a nodulous double belt, the anterior one 

 the most prominent : on this the nodes are more spinous in character. 

 The base has numerous granulated spiral bands. 



The margin of the aperture in this specimen is slightly broken 

 towards the anterior extremity, so that the point at the termination 

 of the columellar lip is not quite so well seen, but the aperture 

 itself corresponds in all essential respects with that in T. Phillipsii, 

 and in the group generally. 



Relations and Distribution. — This particular form, in Yorkshire, 

 would seem to be confined to the Cornbrash. It differs from 

 T. Phillipsii in the rather smaller spiral angle, and in the greater 

 number of whorls, and more generally pronounced eucycloid 

 character : as regards ornaments, the granulations of the spiral belts 

 are wider apart, less numerous and nodular, larger and more spiny. 

 There are specimens, however, in the Millepore Rock, which, small 

 though they be, seem to prefigure this form. Amberleya armata 

 belongs to the Turho ornaius group, but the differences are not 

 inconsiderable as compared with typical forms of T. ornatus from 



