220 r,AXD A^TD FRESHWATER 



Size : raajor diam. 4-50, alt. axis 3-0 mm. 



This shell is very close to that of R. hascaw^a ; but placed side 

 by side these difi'eiences are to be uoted : a blunter spire, side of 

 spire more convex, and principally in the umbilicus being very much 

 M'ider. 



IIahula DAFiAENsis, n. sp. (Plate CXVII. fig. 5.) 



Locality. Dikraug Valley, Dafla Hills {G.-A.). 



Shell deeply umbilicated, globosely conoid ; sculpture distant, 

 raised, oblique, sinuate costulation ; colour pale sienna-brown ; 

 spire couic, sides slightly convex ; suture moderately impressed. 

 Whorls 7, convex, indistinctly angular at the periphery near 

 aperture ; aperture semiovate ; peristome thin ; the columellar 

 margin scarcely thickened. 



Size : major diam. 4*2, alt. axis 3*0 mm. 



This interesting form can at once be distinguished by the absence 

 of the lirate sharp keel of R. bascauda and its allies. 



Rahtjla lhotaensis, n, sp. (Plate CXVII. fig. 6.) 



Locality. Lhota Naga Hills, Assam (Chennell). 



Shell openly and deeply umbilicated, pyramidal, base very flat, 

 sharply keeled and cariuate ; sculpture^ costulation close and regular, 

 oblique and sinuate, extending to the basal side ; colour rich brown 

 (burnt-sienna) ; spire conical, apex pointed, sides slightly convex ; 

 suture fairly impressed, with a thin liration. Whorls 7, slightly 

 convex ; aperture quadrate, oblique ; peristome thin, angulate on 

 the lower outer margin ; columellar margin subvertical, not thick- 

 ened, slightly reflected. 



Size : major diam. 5-0, alt. axis 4-9 mm. 



This is a larger species than the type, and can be distinguished 

 by its more pointed ajiex, pyramidal form, and very flat base, and 

 the costulation is much closer and finer. 



Rahula MUNii'URENsis, u. sp. (Plate CXVII. fig. 4.) 



Localiii/. Munipur Hills, north-east of valley. 



Shell globosely conic, deeply umbilicated, rounded below the 

 keel, the liration on which terminates at the penultimate whorl ; 

 sculpture distant, very strong and very regular costulation ; colour 

 pale grey, the ribbing showing bright brown ; spire conoid, side 

 nearly flat ; apex rounded ; suture impressed. Whorls 6, regular, 

 sides very convex ; aperture semicircular ; peristome fairly thick- 

 ened : columellar margin subvertical. 



Size : major diam. 3*5, alt. axis 2-25 mm. 



This is a very distinct little species and the smallest of the genus. 

 I have only found one specimen as yet among the minute Helices I 

 collected in the Munipur Hills. 



