296 W. H. RucUeston—On the Yorlshire Oolites. 



63 . — Nerita minuta, Sowerby, 1824, var. himidula, Phillips. 

 Plate IX. Figs. 4a, 46, 5a, 5h, 6. 



1824. Nerita minuta, Sowerby, Mineral Conchology, table 463, figs. 3 and 4. 

 1829 and 1835. Natica tumidida, Phillips, G. Y. p. 129, pi. si. fig. 25 {Nerita 



minuta, Sow.). 

 1854. Nerita minuta. Sow. Morr. Cat. p. 264. 



„ Natica tumidula, Phil. Morr. Cat. p. 262. 

 1875. Natica tumidida, Phil. G. Y. 3rd edition, p. 257, pi. xi. fig. 25. 



Compare also 



Nerita ovata, Eoem. Ool. Geb. p. 156, pi. x. fig. 6. 



Bibliographj, etc. — In his first edition Phillips seems to have had 

 an idea that there was a connection between the Dogger shell and 

 Sowerby's very small species (3 mm.) from the Oolite of Ancliff. 

 It must be admitted that Sowerby's enlargement yields a figure very 

 like the Dogger fossil. Morris, however, did not favour this notion, 

 since he quotes Nerita minuta from Anclifi" without any reference to 

 "Natica'" tumidula, which he evidently regarded as distinct. But 

 he refers to Nerita ovata, Eoem., which, although it comes from the 

 " Upper Coral Eag " along with Nerincea nodosa, has a most striking 

 resemblance to the Dogger species. On the whole, I am inclined to 

 believe that Phillips had reason in his first reference, and that 

 Nerita m.iniita, of Ancliff, may be regarded as a micromorph of the 

 Dogger fossil now under consideration. Moreover, Sowerby figured 

 Nerita costata [ = costulata, Deshayes) from the same beds at Ancliff, 

 and this species likewise occurs sparingly in the Inferior Oolite of 

 Yorkshire. It is true that Sowerby regarded his species as a doubt- 

 ful Nerite, because of the entire edge of the columella. In Nerita 

 minuta {tumidida), and possibly in N. ovata, Eoem., this is perhaps 

 more apparent than real. 



Lastly, the Yorkshire fossil has been labelled Nerita minuta, 

 Sow., in the Lycett Collection at the Jermyn Street Museum, pre- 

 sumably in accordance with the identification of Lycett himself, who 

 seems to have been satisfied of its character as a Nerite. Under 

 these circumstances there seems no alternative but to adopt Sowerby's 

 name for the fossil so long known in collections as Natica tumidula, 

 PhiL^ 



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

 Wyke) — Jermyn Street Museum. Figs. 4a, 46. 



Height 15 millimetres. 



Eatio of body-whorl to entire height .... about 85 : 100. 

 Spiral angle 125°. 



Shell transversely oval, tumid, imperforate. The spire consists of 

 a small button-like apex, which expands within the course of two 

 or three widely separated volutions into a very large body- whorl ; 



^ The fact that the Ancliff Oolite was supposed to be of Great Oolite age may have 

 had something to do with the unwillingness of some excellent authorities to recognize 

 the relationship of Natica tumidula to Nerita minuta. Although I have made 

 numerous inquiries, I have never been able to obtain any very satisfactory account of 

 the beds whence Sowerby obtained his ' ' Ancliff ' ' fossils, mostly, I believe, either 

 micromorphs or very small species. 



