130 LA.ND AND FRESHWATER 



Macrochlamino', as distinguished from those South-Indian molluscs 

 which may be separated as the Ariophantince. 



In the generative organs, making due allowance for the close- 

 wound shell, which necessarily elongates the different parts, there 

 are several characters indicating the above relationship : — (1) the 

 long spermatheca ; {2} the long kalk-sac or flagellura ; (3) the part 

 near the retractor-muscle attachment of the male organ — only 

 differing, I may here observe, from typical Macrochlamys &c. by 

 a short hook-like c£Ecum taking the place of one more or less 

 coiled (Plate XXVIII. figs, la, \ h) ; (4) a right shell-lobe, 

 although ver}' reduced in size, is present ; (5) the radula is of 

 the same type, a few teeth on the margin aculeate. 



Its subgeneric rank is supported by the form of the shell and its 

 seuljDture. If this conchological character only be considered, many a 

 genus of the MoUusca has been founded on differences less appre- 

 ciable than are to be found in Khasidla vidua and Macrochlamys 

 Jiai'dwickei. 



Khasiella vidua, W. T. Blf. (Plate C. figs. 1-5 d.) 



Euplecta vidua, W. T. Blf. Journ. A. S. B. vol. xlix. pt. 2, 1880, 

 p. 190, pi. ii. figs. 2 & 5. 



Helix vidua, Blf. MSS. ; Hanley, Conch. Ind. p. 52, pi. cxxx. 

 figs. 2, 3. 



Nanina climacterica, Bs. (var, vidua of Conch. Ind.), Nevill, 

 Hand-list, p. 30 : Naga Hills, Khasi Hills, Tezpur, and Sibsagar, 

 Assam. 



Nanina (MacrocJilamys) vidua, Tryon, Man. Conch, p. 95. 



Original description: — '■^ Testa iniperforata, conoideo-depressa, 

 superne oblique confertim atque arcuatim Jilifonni-costulata, suhtus 

 Icevigata, polita, radiatim striatula, superne pallide cornea, subtus 

 pallidior. Sjyira depresso-conica, lateribus suhrectus ; apice acuti- 

 usculo, sutura impressa. Anfr. 8, convexi, arcti, lente accrescentes ; 

 ultimus superne ad lieripheriam angulatus, antice vix deseendens, 

 subtus convexus. Apertura obliqua, lunaris, latior qiiam alta. 

 Peristoma obtusum, leviter siyiuatum, intus vix albo-labiatum, margine 

 basali arcuato, columellari vix re/lexo. 



" Diam. maj. 17, min. 15|, axis y| mm. 



'^Hab. in montibus Garo, Khasi et Naga dictis, vallem Assamensam 

 meridiem versus contingentibus (Masters, Godivin-Austen). 



" Varietas minor, depresso-tiirbinata, spira conica. 



" Diam. maj. 14, min. 12^, axis 9 mm. (Plate ii. fig. 2.) 



" Hab. cum prsecedente. 



" Shell imperforate, conoidly depressed, above ornamented with 

 oblique, close, and arcuate fine hair-like costulation, smooth and 

 marked with radiating striae below ; pale horny, paler beneath. 

 Spire depressedly conical, the sides nearly straight, apex rather 

 sharp, suture impressed. Whorls 8, convex, narrow, slowly in- 

 creasing in size, the last angulate above at the periphery, scarcely 

 descending towards the mouth, convex below. Aperture oblique, 



