1918. J N. Annandale: 3IoUvscs of the hiJe Lake. 131 



the lower edge of the whorl. All the ridges are more or less granular. 

 This is the case to a greater extent in the two median ridges. The 

 microscopic sculpture is much as in the upper w^horls. There are three 

 irregular ridges on the upper part of the body-whorl, often tending to 

 split up transversely and always irregularly nodular. The longitudinal 

 striae on this part of the shell are much coarser and more irregular, 

 and the transverse striae much less apparent. The fourth spiral ridge 

 on the body- whorl consist mainly of a row of low squamous projections, 

 which are not at all spiniform. Below it there are three or four 

 irregular ridges, nodular, sub-nodular or undulate on the surface. 



Measurements of shells. 



Total length 



Greatest breadth (without projections) 



Length of spire (on dorsal surface) 



Length of aperture 



Breadth of aperture ... 



I have given the measurements of the two most perfect adult shells 

 we obtained, the first of which I have selected as the type-specimen ; 

 but most of our specimens are broken, and some must have attained 

 a considerably larger size. 



Type-specimen. M. 11028/2, Zoological Survey of India {Ind. 

 Mus.). 



We obtained over twenty more or less complete specimens in the 

 cave-deposits in which the type of Taia ohesa was also found, in the 

 Hsin-Dawng valley a few miles east of the town of Yawnghwe. 



Taia lacustris, sp. no v. 



Plate XV, figs. 10, 11 ; plate xvii, fig. 1 ; 

 plate xviii, figs. 7-9. 



The shell of this species resembles that of T. cylindrica but is con- 

 siderably smaller, less elongate and less oblique in the body-whorl. Its 

 sculpture is more prominent, and at the same time less definitely 

 nodular. There are two obtuse spiral ridges on the fourth whorl and 

 four on the fifth. The projections on the chief ridge of the body-whorl 

 are irregular and have a less definitely squamous character. The 

 aperture is relatively smaller and less oblique in its longitudinal 

 and transverse axes. The columellar callus is even broader and 

 distinctly more prominent. It retains a fine oily lustre even in the 

 fossil shell. 



Measurements of shells. 



Total length 



Greatest breadth (without projections) 



Length of spire (on dorsal surface) 



Length of aperture 



Preadth of aperture ... 



