NERIN AHA. 201 
132. Nerin#a arrenvata, Witchell, 1887. Plate XIII, fig. 6 a. 
1887, Nerinma arrenvara, Witchell. Vol. cit., p. 82, pl. i, figs. 7 and 8; pl. ii, 
fig. 6. 
Description : 
Spiral angle ; ‘ ‘ . 10°—12°. 
Height of whorl to width . : 4 ols lesos 
Approximate length : . 60—70 mm. 
Shell conical-elongate, strongly dimorphous. Whorls about twenty; those 
towards the apical end are excavated anteriorly, and the sutural prominence is 
excessive. Later on the sutural ridges disappear, and the whorls are quite flat 
and plain, increasing in the form of a regular cone. It is probable that the 
earlier whorls were ornamented with fine spiral lines, which disappear with the 
flattening of the whorl. 
Body-whorl smooth and without salience; aperture widely ovate, canal rather 
wide. Section triplicate; an obtuse fold on the outer wall, one very low on the 
columella, and one on the posterior wall. 
Relations and Distribution.—Although obviously related to Nerinea oolitica, 
this species differs in its more marked dimorphism, and in the extremely conical 
figure produced by the lower whorls. The whorls are also relatively rather 
higher than in the majority of specimens of N. oolitica, and there are slight 
differences in the internal section. 
It has been found in the Pea-grit of Longfords, in the Oolite Marl of 
Swift’s Hill and Longridge, and possibly also in the Lincolnshire Limestone at 
Belmisthorpe. 
133. Nermnma ExpPANsa, sp. nov. Plate XIII, fig. 60. 
Description : 
Spiral angle : : : SD ie: 
Height of whorl to width . : on eas 05 
Approximate length ; : . 90—100 mm. 
Shell conical-elongate, the spire exhibiting a moderate amount of dimorphism. 
Number of whorls about eighteen, increasing by steps, but not much excavated, 
and with only a moderate sutural prominence; the subapical whorls show traces 
of fine spiral lines. The later whorls are smooth, nearly flat, and without 
prominence, whilst the suture is close or even depressed. The aperture is 
ovate-oblong, and section similar to that of N. oolitica. 
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