62 JF. E. Hadleston—On the Yorkshire Oolites. 



a more widely angled and less pupoid shell, possessed of a more 

 complex system of ornamentation, and mucb. more strongly turrited. 

 The specimen is unique, as far as I know. 



28. — Cerithium (Kilvertia) Comptonense, sp.u. Plate III. 



Fig. 14. 



Description. — SiDCcimen from the Millepore Rock of the coast 

 (zone 2). Leckenby Collection. 



Length of the entire shell 6 millimetres. 



Width If ,, 



Eatio of body-whorl to entire shell, nearly as .... 1 : 2, 



Shell extremely small and short, with an obtuse apex ; whorls 6 

 in number, the body-whorl being relatively large ; sutures close and 

 the sutural inclination slight. SjDirals 4 in number, judging from 

 the penultimate, where alone the ornaments can be determined with 

 accuracy : three of these are distinguished by large oval granulations, 

 extended spirally, but arranged to form the thick tuberculated costal 

 so characteristic of the spire. The spirals in the base of the body- 

 whorl are strongly marked, but not tuberculated. Aperture involved. 



Relations and Distrihution. — This curious little shell is so situated 

 in the matrix that it has not been possible to ascertain for certain 

 whether it possesses the thickened oi-bicular aperture said to be 

 one of the characteristics of Kilvertia (Lycett, Suppl. to Grt. Ool. 

 Moll. pp. 8 and 15), a subgenus instituted to receive a number of 

 pygmy forms chiefly known in this country from Bathonian beds. 



As regards Yorkshire the specimen is unique, but there exists in 

 the Jermyn Street Museum a solitary specimen, clearly belonging 

 to this species, said to come from the Inferior Oolite of Compton ; V 

 hence the name selected. 



29. — Cerithium, or Tureitella, sp. PI. III. Fig. 15. 



Description. — Specimen from the Dogger Sands (lower part of 

 zone 1), Blue Wyke. Leckenby Collection. 



This specimen is too imperfect for accurate measurements, but 

 the fragment indicates a turrited univalve with a spiral angle of 15°, 

 and very wide suture. As there is no trace of aj^erture, it is difficult 

 to say whether this form should be classed under Cerithium or 

 Tnri-iteUa. Judging from analogy with other shells about this 

 horizon, the openness of the suture is rather in favour of regarding 

 it as a Turritella. The number of the spirals (4), and the prominence 

 of the third one, would seem rather to connect it with Turritella 

 quadrivittata, presently to be described. Yet there is a somewhat 

 spiny character about the nodes, and certain traces of longitudinal 

 ornament, which altogether fails in the Turrilellce of the Dogger, 

 where the ornamentation partakes more of the nature of spiral belts. 



In the enlargement of this ill-preserved specimen too much 



prominence has perhaps been given to the third spiral. There is no 



other specimen exactly like it in the Leckenby Collection ; but there 



is a small Cerithium, also from the Dogger Sands, which may belong to 



1 No one seems to know exactly where this place is situated. 



