122 Records of the Indian Museum. [Vol, XIV, 



part of the whorl. The whole shell ornamented with coarse, more or 

 less sinuous longitudinal striae. The varix, which is not well-defined, 

 running a short distance above the lip, but not precisely parallel to it, 

 on the central part of the whorl. 



Measurements of shells. 



Total length ... 



Greatest breadth 



Length of aperture 



Greatest breadth of aperture ... ... 2-5 3 3 



The radular teeth and external male organ are figured on pi. XIV. 

 The latter differs considerably from that of P. nassa. The inner 

 branch is much longer, distinctly annulated and not at all expanded 

 at the tip ; the outer branch is irregularly annulated and narrowed 

 abruptly a short distance before its apex, which is blunt. 



The foot is quadrangular, expanded in front, truncated behind, 

 with a slight median posterior notch. The outline of the posterior 

 extremity is, however, subject to considerable variation. The outline 

 of the anterior margin is sinuous. The proboscis is stout and short 

 and notched in front, it does not extend quite so far forward as the 

 anterior margin of the foot. The tentacles are slender and tapering, 

 not quite as long as the shell when fully extended. All the soft parts 

 extruded from the shell are bright olivaceous, speckled with golden 

 green. 



The operculum is broadly ovoid, bluntly pointed posteriorly ; the 

 central part is thick and almost porcelainous, but translucent ; the 

 membranous marginal border is rather broader externally than inter- 

 nally. The outer surface is flat with a small depression round the 

 nucleus, which is less clearly spiral than in H. nassa. There is a strong 

 semi-circular ridge running round the outer margin of the thickened 

 region on the inner surface. 



Type-specimen. M. 11113/2, Zoological Survey of India {Ind. Mus.). 



This species is extremely abundant in all parts of the Inle Lake 

 and also in swamps at He-Ho. It is found in much smaller numbers 

 in ponds near Yawnghwe. I can discern no constant difference 

 between shells from different localities or types of habitat, except 

 that those from He-Ho are slightly smaller than those from the Inle 

 Lake, 



Genus Amnicola, Gould k Haldeman. 



I assign provisionally to this genus a species which apparently 

 differs from the American forms in having a testaceous operculum. 



Amnicola alticola, sp. nov. 

 Plate xiv, figs. 6, 6a. 



Shell ovately fusiform, moderately elongate, minute, thin, trans- 

 parent, chestnut-brown, sculptured with very minute longitudinal striae 

 set close together, otherwise smooth, strongly opalescent internally, 



