56 W. R. RucUeston—The Yorkshire Oolite. 



43. — Tdkbo (Delphinula) Pellati, De Loriol, 1874. Plate III. 



Figs. 8rt, h. 



Delphinula FeUati, De Loriol, 1874, De Loriol & Pellat, Jurass. Supr. de 



Boulog'ue, p. 115, pi. iz. figs. 34 and 36. 



Description. — Pragraent from tlie Coral Eag of Langton Wold 

 (my Collection). 



The external portion of the whorl is strongly bicarinated, and 

 widely umbilicated. The keels carry thick spinous projections, those 

 of the posterior keel being the strongest; the intermediate space 

 between the two keels is excavated. The base of the last whorl is 

 penetrated by a great umbilicus, funnel-shaped and bounded by a 

 smooth belt, below which the sides of the excavation are marked by 

 fine strige of growth. 



Relations and Distribution. — This fragment so well fits the very 

 complete description given by De Loriol that there can be little 

 doubt as to the identification. The original specimens were obtained 

 from the Sequanien of Boulogne. Although Buvignier has described 

 and figured some half dozen species of Delphinula from the 

 Corallian of the Meuse, none exactly fit this one. Since the 

 Boulogne beds have not, as a whole, any strong affinity with the 

 Corallian of Yorkshire, this identification forms an interesting 

 exception. The Yorkshire specimen is at present unique ; it was 

 found in one of the quarries on Langton Wold, where so many 

 curious fossils have been discovered. It may be looked for in the 

 Coral Eag of Upware. 



Genus Trochus, Linnseus, 1758. 

 This genus is but poorly represented in the Corallian rocks of 

 Yorkshire. The species are small in size and few in number ; yet 

 even these have been overlooked, since Phillips, in his last edition, 

 does not enumerate a single Trochus. On the other hand, Buvignier 

 has described about fifteen species from the Coral Eag of the Meuse, 

 of which two or perhaps three may be approximately identified in 

 our beds, whilst one or two species have not at present been noted 

 elsewhere. 



44 — Trochus obsoletus, Eoemer, 1836. Plate III. Fig. 9. 



Trochus obsoletus, Eoemer, 1836, Ool. Geb. p. 151, pi. xi. fig. 5. 

 Trochus inornatus, Buvignier, 1852, Stat. geol. de la Meuse, p. 37, pi. 26, figs. 23, 



and 24. 



Description. — Specimen from the Passage-beds in the Lower 

 Limestones at Wydale (my Collection). 



Length 7"5 millimetres. 



Width 8- 



Spiral angle 75°. 



Shell conical, slightly oblique, not umbilicated. Whorls four or 

 five in number, very regular, smooth and nearly flat, suture but 

 slightly accentuated. Aperture broken away. 



Relations and Distribution. — An average form, which probably 

 occurs with slight modifications on several horizons. Buvignier's 

 specimens, which are rather larger, occur rarely in the ferruginous 



