NERITA. 333 
minuta, as pointed out by Cossmann (loc. cit.), but that is a very different thing from 
our accepting the view that Nerita minuta and Nerita costata are different stages of 
the same species. The figures of d’Orbigny are altogether beside the mark, as 
his artist evidently had no idea whatever of Nevrita costata. Specimens from the 
Pea-grit, except as to size, very much resemble the Ancliff fossil, and we can trace 
the costate form in the very earliest whorls. Consequently, as far as the Inferior 
Oolite is concerned, I cannot agree to the union of these two species of Sowerby, 
and must continue to regard Nerita minuta as a distinct fossil. The Nerita minuta 
figured by Cossmann is evidently Sowerby’s Nerita costata = costulata, Deshayes. 
Description : 
Height . ; : : average 9 mm. 
Width . : : . 11—12 mm. 
Shell transversely ovate, tumid, moderately thick; variable in size, but rarely 
exceeding 15 mm. in width. Spire small and depressed, consisting of about two 
and a half whorls, which are costated and sunk in a deep sutural channel. Body- 
whorl relatively large, constituting about nine-tenths of the total height, and 
flattened posteriorly so as to impart a certain degree of angularity to the shell, which 
is ornamented throughout with numerous and rather fine radial cost, closely set 
and deflected posteriorly. Aperture large ; columellar lip wide and flat, but without 
denticulation of the inner margin. 
Relations and Distribution.—This species may be regarded as one of the most 
typical Nerites occurring in the Lower Oolites. The most numerous and best 
preserved specimens occur in the Pea-grit of Crickley Hill, where they are seen to 
differ somewhat in shape; here and there a specimen being unusually transverse, 
as though approaching the contour of Nerita Buvignieri of the Great Oolite. The 
shorter specimens exhibit a tendency to merge into the species next described. In 
the Yorkshire beds Nevita costulata is rare, being generally represented in the 
Dogger by Nevrita pseudo-costa (perhaps only a variety), whilst in the Scarborough 
Limestone it seems to pass into a more rugose form. 
266. Nenrita pseupo-costata, d’Orbigny, 1850. Plate XXVIII, figs. 7, 8, and 9. 
1829 and 1835. Nerrra cosrara, Sow., sp. Phillips, Geol. Yorks., pt. 1, pl. xi, fig. 32. 
1850. —  psEupo-costata, d’Orb. Prod., i, p. 264 (non Gmelin, 1789). 
Blue Wick. 
1854. _ — — Morris, Cat., p. 264. Blue Wick. 
1884. _ — —  Hudleston, Geol. Mag., dee. 3, vol. i, 
p- 298, pl. ix, figs. 7, 8, and 9. 
Cf. also —  cosrirera, Piette. Cossmann, Et. Bath., p. 156, pl. xvii, figs. 59 
and 60. 
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