298 7F. E. Rudleaton—On the Yorhhire Oolites. 



Neither is any species of Nerita quoted by Braims from the Middle 

 (Brown) Jura of N.W. Germany, 



An unornamented species like this would natually pass upwards 

 with but little modification. Although nothing of the kind is known 

 to me from higher beds in Yorkshire, yet in Neritina CooJcsonii, 

 Deslong.^ (vol. cit. p. 133, pi. 10, figs. 8 and 9), we see a consider- 

 able outward resemblance ; but in specimens from the Great Oolite 

 of Normandy the pillar-lij), judging by the figure, seems to have 

 encroached to an amazing extent upon the aperture. Allusion has 

 already been made to the resemblance of Nerita ovata from the Coral 

 Eag of N. W. Germany. 



62. — Nerita pseudo-costata, D'Orbigny, 1849. Plate IX. Figs. 



7, 8 and 9. Each enlarged twice. 

 1829 and 1835. Mrita costata (Min. Conch.), Phillips, G. Y. p. 129, pi. v. fig. 32. 



York. Mas. 

 1849. Nerita pseudo-costata, WOrh. Prod. i. p. 264. (Et. Bajocien.) 

 1854. Nerita pseudo-costata, D'Orb. Morr. Cat. p. 264. 

 1875. Neritopsis pseudo-costata, D'Orb. Phillips, G. T. 3rd ed. p. 258, pi. ix. 



fig. 32. 

 Non Nerita pseudo-costata, D'Orb. Morris and Lycefct, Gt. Ool. Moll. p. 114, 



pi. XV. fig. 3. 



Bihliogra'pliy, etc. — The history of Nerita in the Yorkshire Oolites 

 seems doomed to be involved in an ever recurring tissue of mistakes. 

 In the first place Phillips appears to have been wrong in his identi- 

 fication of the Dogger shell now under consideration, though small 

 blame can attach to him for regarding Sowerby's Nerita costata 

 (from Anclifif) as identical with his Yorkshire fossil. D'Orbigny 

 set him right; but that author, it should be observed, does not 

 describe or figure N. pseudo-costata in the Terrain Jurassique, whence 

 we may infer that no such form had been noted from any locality in 

 France. Then came Morris and Lycett. who described and figured 

 as the Nerita pseudo-costata of D'Orbigny a shell which " appears to 

 be identical with the well-known Inferior Oolite species." This was 

 stated to occur near Scarborough (i.e. in the Scarborough Limestone), 

 and also in the Inferior Oolite (i.e. the Dogger), 



Their mistake seems to have been exactly the converse of that of 

 Phillips. The fossil figured by them was indeed and in truth no 

 other than Sowerby's Inferior Oolite fossil. Subsequently (1875) 

 Phillips referred the species now under consideration to Neritopsis, 

 on what grounds I am at a loss to conceive. 



Description. — Specimens from the Dogger (zone 1), Peak (Blue 

 Wyke).^ Leckenby Collection, 



Height 9 millimetres. 



Body-whorl to total height about 90 : 100. 



^ D'Orbigny, Terr. Jurass. p. 231, gives the following extraordinary synonymy: 

 Nerita tninuta, Sow. 1824. 

 Nerita costata, Sow. 

 Nerita costulata, Desh. 



Neritina Cooksonii, Deslong. p. 133, pi. 10, figs. 8 and 9. 

 ^ Since the three specimens figured were all attached to a card, it was thought best 

 not to interfere with this arrangement. The dimensions refer to Figure 7, which is 

 slightly the largest. 



