68 



Records of the Ixdian Museum. 



[Vol. XXII, 



view of the shell published by Hanley and Theobald. Fortu- 

 nately, however, some of Benson's co- types are preserved in the 

 Indian Museum, and I have, therefore, thought it desirable to give 

 a complete description and accurate figures of a full-grown shell. 

 It may also be mentioned here that I failed to discover any more 

 specimens of the species in the type locality at Bhim Tal in August^ 

 1920, whence Benson's s])ecimens were obtained, nor did I find any 

 in the tanks at Moradal^ad, where Benson introduced living speci- 

 mens. 



The shell of this species is conico-ovate, twice as long as 

 broad; with an obtuse apex, sometimes decollate; consisting 

 of 5J-6 whorls and of a light olive colour. The whorls increase 

 somewhat irregularly and are not very tumid. The .suture 

 is oblique, curved and somewhat canaliculate, the whorls them- 

 selves being a little flattened just next to it. The first whorl is 



Text-fig. I. — ShuUs of Tricula. x 1?. 



(n) Dorsal \iew of 7". motitana, Benson, 



(i) Ventral view of the same. 



(c) Dorsal view of T. gravelvi. Prashad. 



irf) Ventral view of the same. 



minute, the penultimate whorl is band-shaped and comparatively 

 more swollen than the other whorls ; the body-whorl, which is not 

 very tumid, is 2| times as broad as the penultimate whorl, it is 

 roughly trigonal or subtrigonal in both dorsal and ventral views. 

 Its upper surface is somewhat flattened but not angulate, the 

 inner margin is regularly arched and ends in a short projecting 

 lobe corresponding to the inner angle of the mouth, the outer 

 margin is sharply curved and is continued with the regularly 

 curved ventral margin to form the lobe noted already. The mouth 

 is large, oblique, ovoid, pointed above and has a part of the 

 peristome curved over its angle. The peristome is continuous, but 

 the columellar callus is narrow and of unequal width, the outer 

 and lower margins of the mouth are only slightly re-curved. The 

 shell is subumbilicate. 



Distribution. — The original series of specimens was found 

 attached to the stems and leaves of an aquatic plant in a stream 



