BEffSONIA. DALINGIA. 177 



short ; the ainatorial organ long and much twisted, and the two 

 organs, as packed within the animal, lie respectively on the right 

 and left sides. The spermatheca is very long. The genitalia are 

 not at their full development : they would at the pairing-season 

 be much more swollen. 



There is a central projection to the jaw. 



The radula shows the formula 



+ 25 . 2 . 17 . 1 . 17 . 2 . 25 4- 

 + 44 . 1 . 44 + 



About twelve of the outermost teeth are very minute ; bicuspid 

 teeth follow, the inner cusp being much the longest. The centre 

 tooth is tricuspid, the admedians bicuspid, the outer small cusp 

 situated rather lower than usual from the main point. 



The absence of the shell-lobes and the long spermatheca place 

 this species in the genus Bensonia. I would point out the 

 very interesting resemblance it has to Macrochlamys turgurium, 

 inhabiting the same area externally noticeable in the coloured 

 border to the peristorne and the markings of the body seen 

 through the shell ; internally in the generative organs ; snowing 

 how closely Bensonia approaches Macrochlamys.'] 



275. Bensonia nepalensis, Blf. (Nevill, MS.) P. Z. S. 1904, ii,p.441, 

 pi. 25, fig. 1 ; Nevill, Hand-L i, 1878, no. 67, p. 27. 



Shell openly perforate, conoidly depressed, sublenticular, thin, 

 obliquely and rugosely plicate above, smoother and striated below, 

 without any decussating lines ; spire depressedly conoid, suture 

 slightly impressed ; whorls 6, convex, regularly increasing, the 

 last not descending, keeled at the periphery, the keel becoming 

 blunter near the aperture, tumid below ; aperture oblique, roundly 

 lunate, the margins converging ; peristome thin, columellar margin 

 regularly curved, vertical above, reflected throughout, broadly at 

 the perforation. 



Major diam. 23|, min. 21, height 12 mm. 



Hab. Khatmandu, Nepal. Types in the British Museum 

 ( Godwin-Austen). 



This shell is near B. camura, but is distinguished by a lower 

 spire, smaller umbilicus, stronger sculpture, and the absence of 

 decussating striation, and by less acute carination. The animal is 

 not known. 



[Subgenus DALINGIA. 

 Dalingia, Godwin- Austen, Mol. 2nd, ii, 1907, p. 149. 



Type, D. bhutanensis, Godwin-Austen. 



Range. Hitherto found only on the Sikhim-Bhutan frontier. 



Shell depressedly conoid, tumid, thin and delicate ; whorls few. 

 Animal has no shell-lobes ; there are three peripodial grooves (a 

 very unusual character). The retractor muscle of the male organ 

 given oil from a large oval mass. No amatorial organ.~] 



TS 



