204 GASTEROPODA OF THE INFERIOR OOLITE. 
Description : 
Spiral angle : ; ; . 3 —4°, 
Height of whorl to width : : = i ivnearly: 
Approximate length . : . 200 mm. 
Shell cylindrical. Whorls numerous, en 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 5) 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 Distribution.—Differs from N. pseudocylindricain having a smaller 
spiral angle and slightly higher whorls. It seems to be the most cylindrical of all 
the Nerinwas 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 6) the whorls are not quite so high. 
137. Nertmnma Houpiestontana, Witchell, 1887. Pl. XIV, fig. 1. 
1887. Nertn#a Hupiestontana, Witchell. Vol. cit., p. 31, pl. i, fig. 4. 
Description : 
Spiral angle . : : palo 
Height of whorl to midi ‘ 5 =) eltsikeo: 
Approximate length =. : . 75mm. 
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. 
Relations and Distribution —Regarded by Mr. Witchell as resembling a Nerineza 
from the Inferior Oolite of Whitwell in Yorkshire (see ‘Geol. Mag.,’ dec. 3, 
vol. i, p. 112, pl. iv, fig. 7). The Yorkshire specimen has suffered so much from 
compression as to make the identification somewhat doubtful. Differs from the 
