TF. H. Hudleston—The Yorkshire Oolite. 55 



Bibliograplnj, etc. — It is so rare to find a good specimen of this not 

 very common fossil, that Phillips may be forgiven for his imperfect 

 figure, whilst no blame can attach to Buvignier for not having 

 recognized Phillips' species. Indeed, there may be differences 

 betvs^een the Yorkshire shell and that of the Meuse (magnified 

 doubtless in figures), which would induce some to separate them 

 specifically. Buvignier's description tallies better than any of his 

 figures. The shells figured by De Loriol from the Sequanien of 

 Boulogne may belong to this species. At the same time that author 

 exercises a wise discretion in hesitating to connect his shells with 

 the Turbo muricatus of Sowerby, seeing that this very abundant 

 fossil has nothing in common with the genus Delphinula. The 

 following extract from Buvignier (Stat. geol. de la Meuse, p. 35) 

 bears upon this subject : 



" M. d'Orbigny, qui n'admet pas de Littorines dans les terrains 

 jurassiques, a probablement confondu cette espece avec le Littorina 

 muricoides, Desh., qu'on trouve dans le meme gissement, mais qui 

 n'a ni la bouche entiere et circulaire, ni les tours disjoints qui font 

 du D. miu-icata une des Dauphinules les mieux caracterises." 



Description. — Specimen from the Coral Eag of Brompton (Strick- 

 land Collection). 



Lengtli 23 millimetres. 



Width '21^ „ 



Spiral angle 75". 



Shell turbinated, nearly as wide as long, umbilicated. The spire 

 consists of about five whorls, which increase regularly and rapidly, 

 and are very open, and separated by a broad suture. They are 

 ornamented with very coarse scaly ribs arranged transversely ; on 

 the penultimate these are five in number. Some of the ribs towards 

 the posterior part of the body-whorl are strongly muricated. The 

 ribbing is continued of almost equal strength throughout the base 

 of the shell, and the umbilicus is bordered by a band with rather 

 stronger serrations. The aperture is perfectly circular, with a very 

 thick peristome, which is free and with crenulated edges. Umbilicus 

 well marked. 



Relations and Distribution. — Sir Charles Strickland's shell, besides 

 being in a better state of preservation, is larger than an average of 

 Yorkshire specimens, which also vary slightly in ratio of length to 

 width, and seldom have so deep an umbilicus. The relations of this 

 species to other members of the genus Delpldmda are not very clear 

 at present, and it would be difficult to point out its representatives 

 in the English Jurassic rocks. Buvignier describes D. inuricata as 

 rare in the " Oolithe ferrugineuse " above the Oxford Clay. In 

 Yorkshire the corresponding form occurs chiefly in the Coral Rag of 

 the Scarborough district, and in the base of the Coralline Oolite at 

 Pickering. I am not aware that it has b'aen noted in other parts of 

 Eng-land. 



