NERITA. 335 
Scarborough, and in the Northampton Sand at Duston, thus appearing on two 
different horizons of the Inferior Oolite. 
Tue smooth Nerites—Neridomus, Morris and Lycett. 
There is more than ordinary difficulty as regards nomenclature in this group, 
part of which has originated in the interpretation placed upon that very trouble- 
some and obscure micromorph, Nerita minuta, Sow. I have endeavoured to focus 
the smooth Nerites of our Inferior Oolite under two names. ‘There are also afew 
forms which could not be thus arranged, but as the indications are obscure I have 
concluded not to attempt them. 
268. Nerira (Neripomus) tumiputa, Phillips, 1829. Plate XXVIII, figs. 12 a, 12d. 
1829 and 1835. Navica tumrputa, Phil. Geol. Yorks., pt. i, pl. xi, fig. 25. (Nerita 
minuta, Min. Conch., pl. cecelxiii ?). 
1854. —_ —_— — Morris, Cat., p. 262. 
1884. Neritra minuta, Sow., var. TuMIpULA, Phil. Hudleston, Geol. Mag., 
dec. 3, vol. i, p. 296, 
pl. ix, figs. 4a, 46, 5a, 
5b, 6. 
Bibliography, §c.—Morris in his Catalogue, it would seem, did not favour the 
view that “‘ Natica”’ twmidula, Phil., was to be regarded either as a synonym or 
variety of Nerita minuta, Sow. On the other hand, the Yorkshire fossil has been 
labelled Nerita minuta, Sow., in the Lycett collection of the Jermyn Street Museum, 
presumably in accordance with the identification of Lycett himself. 
Description.—Measurements of a specimen from the Dogger: height 11 mm., 
width 11 mm. 
Shell ovate, tumid, smooth, and but shghtly oblique, the height and width 
being nearly equal. The spire is composed of a small button-like apex, expanding 
in the course of two or three widely separated volutions into a large body-whorl, 
which exhibits a slight posterior flattening, whilst the rest of the whorl is globose, 
and without ornament other than fine lines of growth. No colour markings are 
visible in the Dogger shells, the matrix not being favorable. 
Aperture large, outer lip crescent-shaped and thin ; inner lip thick, subconvex, 
and slightly sinuated, without denticulations on the margin. N.B.—In the 
majority of specimens, as in the one figured, there is a slight abrasion of the 
