54 TT. H. Radleston—The Yorkshire Oolite. 



suture. The body-whorl is greatly larger than the rest of the spire, 

 and has the posterior area slightly flatted. Base solid and rather 

 tumid. The aperture is oblique, and not sufficiently well preserved 

 to show the indentation on the columella. 



Relations and Distribution. — This may be deemed one of the 

 representatives on a higher horizon of Monodonta (Nerita) IcBvignia, 

 Sow. (Min. Conch, pi. 217, fig. 1), which was originally described 

 from the Inferior Oolite of Dundry. Except that this latter shell is 

 slightly more Neritoid, and not quite so wide, the differences are 

 not very great. Doubtless such a form, with modifications, might 

 be expected to run throughout the Jurassic rocks. In Yorkshire 

 this particular form is rare. 



41.— TuKBO L^vis, Buvignier, 1852. PI. III. Fig. 6. 

 Turbo Imvis, Buviguier, 1852, Statis. geol. de la Meuse, p. 37, pi. 26, figs. 29, 30. 



Bibliographi/, etc. — We have already seen that Turbo Icevis, Buv., 

 was regarded by D'Orbigny as being identical with his Turbo Erinus, 

 but the proportions do not coi'respond. Buvignier's T. Icevis comes 

 very near to Monodonta papilla, Heb. & Desl. (Bulk Soc. Linn. 

 Norm, tome v. p. 211, pi. iii. fig. 1), which fossil is recognized by 

 De Loriol and Pellat (Jurass. Supr. vol. i. p. 121, pi. ix. figs. 23, 

 24) as occurring in the " Sequanien " of Boulogne. 



Description. — Specimen from the Coral Rag of Hildenley (Strick- 

 land Collection). 



Length 9 millimetres. 



Width 9 



Spiral angle 75°. 



Shell subconical, globular, equally wide as high. The spire 

 consists of about five whorls, smooth, convex, and distinctly separated 

 by a suture. Body- whorl very large, globose, with a slight tendency 

 to flattening of the posterior area. Base tumid. Aperture involved 

 in matrix. 



Belations and Distribution. — The proportions of this unornamented 

 Turbo separate it from the species last described, with which, how- 

 ever, it may be deemed to share affinities in the original Monodonta 

 (Nerita) laevigata, Sowerby. Buvignier's type of T. Icevis is only 

 two-thirds the size of the Yorkshire specimen now figured, but the 

 proportions correspond exactly. It is stated to be common in the 

 White Oolite of the Coral Rag of St.-Mihiel. 



In Yorkshire Turbo Icevis is sparingly distributed throughout the 

 Coral Rag, and is, perhaps, the most usual of the three unornamented 

 forms of Turbo, which have hitherto been lumped under the general 

 designation of Nerita Icevigata. 



42. — TuKBo (Delphintjla) funiculatus, Phillips, 1829. Plate 

 III. Figs, la, b. 

 Turbo funiculatus, Phillips, 1829, Geology of Yorkshire, vol. i. pi. iv. fig. 11. 

 Delphinula muricata, Buvignier, 1843, Mem. Soc. Verd. p. 243, pi. iv. figs. 31, 32. 

 Idem. Idem. 1852, Stat. geol. de la Meuse, p. 35, pi. 32, figs. 



19-21. 

 ? Delphinula muricata, Buv. De Loriol & Pellat, 1874, Jurass. Supr. de Boulogne, 



p. 113, pi. ix. figs. 30-33. 

 Littorina funiciolata, Phillips, 1875, G. Y. 3rd edition, pp. 258, 325. 



