204 GASTEROPODA OF THE INFERIOR OOLITE. 



Description : 



Spiral angle . . . . 3°— 4°. 



Height of whorl to width . . .1:1 nearly. 



Approximate length .... 200 mm. 



Shell cylindrical. Whorls numerous, high, with a very oblique suture. 

 The extreme apical conditions are unknown. In the subapical stage (fig. 10 a) 

 the spire can scarcely be described as turrited, although the posterior margin 

 of each whorl shows a slightly raised rim. In this stage the whorls are slightly 

 constricted, and ornamented by numerous very fine spiral lines. In the mature 

 stage (fig. 10 b) the whorls are quite flat and smooth, and a simple line indicates 

 the suture. 



Body-whorl smooth and without salience ; aperture narrow-oblong ; canal 

 relatively long. Section triplicate, one large obtuse fold occupying a considerable 

 portion of the centre of the outer wall ; a small acute fold very low down in the 

 columella ; a prominent fold at the junction of the columella with the posterior 

 wall. 



Relations and Bistrihution. — Difiers from N . pseudocylindrica in having a smaller 

 spiral angle and slightly higher whorls. It seems to be the most cylindrical of all 

 the Nerinseas of the Inferior Oolite. Somewhat rare in the Pea-grit near Stroud 

 and at Longfords ; occurs also on the same horizon at Crickley. In the specimen 

 from Weldon (fig. 10 h) the whorls are not quite so high. 



187. Nerin^a Hudlestoniana, WitcheU, 1887. PL XIV, fig. 1. 



1887. Nerinjea Hudlestoniana, WitcheU. Vol. cit., p. 31, pi. i, fig. 4. 

 Description : 



Spiral angle . . . . .15°. 



Height of whorl to width . . . 1 : 1*5. 



Approximate length . . . .75 mm. 



Shell subconical. Whorls about fifteen, deeply excavated in the centre and 

 short. Sutural carina thick and very prominent. Apical condition and ornaments 

 unknown. Section triplicate ; one rather prominent fold on the outer wall, a small 

 acute fold low down on the columella, and a very narrow fold on the posterior wall. 

 Uelations and Distribution. — Regarded by Mr. WitcheU as resembling a Nerinsea 

 from the Inferior Oolite of Whitwell in Yorkshire (see ' Geol. Mag.,' dec. 3, 

 vol. i, p. 112, pi. iv, fig. 7). The Yorkshire specimen has suffered so much from 

 compression as to make the identification somewhat doubtful. Differs from the 



