1919.] The Occurrence of Cyprea nivosa Broderip. 139 
The narrow aperture divides unequally the feebly convex 
ventral surface. It is nearly vertical and nearly straight except 
near its posterior termination where it is slightly bent poste- 
e left. 
anteriorly where, in consequence of a slight curve of the ‘colu- 
mellar lip, they diverge slightly before the narrow contraction 
of the terminal anterior canal. The posterior notch is moder. 
ately deep, with feebly defined edges, and is deflected to the left. 
towards the spire, the apex of which is situated in the prolong- 
ation of the axis of the notch. The anterior dorsal notch, 
The external callosities of the apertural lips are feebly de- 
veloped : at the anterior termination of the shell they re go 
slightly into short blade-like ridges on either side of the 
minal notch. Elsewhere, they are not sufficiently thickened 
communicate a opege margined appearance to the dorsal 
aspect of the 
The columella is steeply oblique, sometimes nearly verti- 
cal, in which latter case it deviates noticeably from the direc- 
tion of the dawan base of the penultimate whorl. Between 
the straight portion of the columella, its terminal, blade-like 
twisted edge, and the anterior edge of the columellar lip, isa 
well-defined, moderately broad, rather shallow fossula. 
The apertural ge a Y are delicate and well defined. 
On the columellar side they extend deeply into the interior of 
the shell and are divid into two portions by a shallow, nar- 
row longi — a on the inner side of which they occa- 
sionally bifur They are continuous across the anterior 
fossula. The gecol 6 of denticulations along the outer lip 
varies from twenty-five to twenty- rding to the size of 
the individual. Along the columellar lip, the number is from 
twenty-two to twenty-five, but has no relation to the size of 
the shell, the largest available specimen exhibiting, indeed, the 
smallest observed number. 
The dorsal surface is buff or dun-coloured, with crowded 
spots of various sizes of a pale-yellow or whitish tint. The 
junction of the mantle lobes is indicated by a moderately broad 
distinctly deeper colour pervading the rims of the 
notches si stl between the apertural a kalaties 
The internal walls of the shell are of a bluish purple. 
