LIZ Records of the Indian Museum. [Vor. <VELL, 
of numerous curved, flattened ridges or fine ribs separated by 
sharp-cut furrows and themselves composed of numerous sharp 
lesser ridges divided by striae. Transverse striae are ill-developed 
or obsolete. ‘The polish of the surface is exceptionally bright. 
In ventral view the spire appears nearly of the same size as 
in dorsal view and, except that the spiral is of course reversed, has 
much the same appearance. ‘The body-whorl in this view is broad 
and transverse above, with its surface highly convex, but it dis- 
appears rapidly behind the mouth, which is of great relative length 
and nearly in the same axis as that of the shell. The mouth is 
more or less quadrate, narrowly truncate or subtruncate above 
and by no means broadly rounded at its anterior end, where the 
lip is hardly at all expanded or everted. Its upper extremity is 
situated a very short distance below that of the body-whorl The 
lip is sharp and convex in an arc greater than a semicircle. Its 
are is, however, often a little flattened in the middle region and 
the extreme margin is occasionally introverted in this flattened 
part. The callus is well developed but not coarse above, con- 
necting the columellar border with the lip. The columella is 
strongly arcuate. Its expanded border completely or almost com- 
pletely closes the narrowly rimate umbilicus. Below the body- 
whorl the inner edge of the mouth is straight and vertical. The 
sculpture on this surface is not so delicate or regular as on the 
dorsal surface and the polish is less marked. 
As seen from above the shell presents several characteristic 
features. Rapid and regular increase of the whorls is apparent 
and also the flattened upper surface of all the whorls but the apical 
one. It is also evident that the upper surface of the body-whorl 
is not only flattened towards its margin, but deeply hollowed out- 
side the suture, especially in the region near the lip. The lip pro- 
jects from the shell with an almost semicircular concavity in its 
margin and then slopes outwards gradually. 
Measurements (in millimetres) and Proportions of Shells. 
Height <: ce 12°0 110 10°5 8°25 
Maximum diameter as Q°5 8'°5 05 Bors 
Height of mouth a 10°O g'0 8°5 55 
Maximum diameter of mouth 0°5 oes 5'0 3°0 
Maximum diameter to height 
of shell ra seer MIRO) OL 2 Oy shes Tete lee 5 
Maximum diameter to height 
of mouth a cic Sie Tiel S45 miler 3 7s eaaT aoe 
The total height of the shell varies from almost equal to 
1} times the maximum diameter. In young shells it may be as 
much as 14 times as great. The height of the mouth is about 14 
times its maximum diameter and nearly + the total height. Its 
maximum diameter is from about 4 to about # that of the shell. 
The proportions of the height of the spire and the body-whorl vary 
owing to the fact that the former is occasionally almost flat. 
Type-serties. No. 1188s M. Z.S.I. (Ind. Mus.). 
