NERIN AA. 199 
Section C (Trirricatz). 
129. Nerinaza parva, Witchell, 1887. Plate XIII, fig. 2. 
1887. Nerina parva, Witchell. Vol. cit., p. 31, pl. i, fig. 5. 
Description : 
Spiral angle é , 2 Qs 
Height of whorl to width : : pellets 
Approximate length ; . 45 mm. 
Shell cylindro-conical, strongly turrited. Whorks about eighteen, very short and 
increasing by steps. In the earlier whorls the anterior portion is much excavated, 
a feature which accentuates the sudden volutional increase. The depth of the 
excavation continues to diminish until each whorl becomes nearly flat, but the 
step-like character is retained. In the later whorls the width is not quite so great 
in proportion to the height. The hollows are ornamented by fine spiral lines, of 
which there are no traces in the maturer whorls. 
Body-whorl angular and short, with a squarish aperture and very short canal. 
Section triplicate ; one blunt and wide fold a little below the middle of the outer 
walls, one rather wide fold on the columella considerably below the middle, and 
one on the posterior wall. 
Relations and Distribution —Distinguished from the succeeding species by the 
excessive shortness of the whorls, and by their strongly step-like character. It is 
also more free from dimorphism and of smaller growth. Somewhat rare on the 
Oolite Marl horizon of Swift’s Hill and Longridge. 
130. Nera oorrtica, Witchell, 1887. Plate XIII, figs. 4a, 4b, 4c, 4d, 6, and 7. 
1887. Nertnxa oonrrica, Witchell. Vol. cit., p. 30, pl. 1, fig. 1 
Description : 
Spiral angle : : : . 12°—16°. 
Height of whorl to width . : «, ies 140. 
Length A : . 80—120 mm. 
Shell cylindro-conical, turrited. Whorlk twenty to twenty-five, exhibiting much 
dimorphism. The apical whorls, as far as about the middle of the spire, are 
much thickened at the suture and strongly excavated anteriorly, so as to produce an 
appearance of excessive turriting ; they are also ornamented with fine spiral lines. 
Presently the thickening at the suture ceases, the whorls become nearly flat and 
