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



the details of shell-sculpture and in shell-form, while in a few individuals 

 a distinct series of squamous projections occur on the body- whorl ; but 

 the variability is small as compared with that of T. naticoides. The 

 species is, therefore, no more than an extension in one direction of 

 the carinate type of T. naticoides. It apparently lived in a swampy 

 marginal zone which gradually encroached upon the open water of the 

 old lake. 



Two other species, both more remote from T. naticoides, also lived 

 in this lake. They belonged respectively to the conical and the elongate- 

 conoidal types that we shall find also in the other two lakes. The 

 conical type is represented by a somewhat variable species of which 

 only a few shells were obtained. They were found in the same deposits 

 as T. intermedia, but need not necessarily have lived in precisely the 

 same conditions. On account of their resemblance in shell-form to 

 species that live or lived in the Inle and Hsin-Dawng Lakes I have 

 called them T. analoga. The corresponding Inle species lives in the 

 outer parts of the central region. The shell of T. rtrm7o^a has the spiral 

 ridges well developed, and the chief ridge of the body- whorl sometimes 

 bears a series of definite projections, but these projections are not spini- 

 form, and are not arranged in a regular series. The shell is very like 

 that of T. noetlingi (Kobelt) from the Lower Chindwin, but we have no 

 particulars as to the habitat of that species. The third He-Ho species 

 is distinctly conoidal though elongate. We know that it lived in the 

 open parts of the lake, and persisted without change for a considerable 

 period. It is chiefly interesting on account of its relationship to one of 

 the Hsin-Dawng species, T. cylindrica. It was constant in shell-form 

 and not very variable in sculpture. 



All the He-Ho shells are thicker than those from the Inle Lake, but 

 thinner than those from Hsin-Dawng. In the Hsin-Dawng valley 

 we found, in cave deposits, the shells of four quite distinct species of the 

 genus. One of these, represented by a single shell, is T. theohaldi ; the 

 other three belong to the same three types as those from the He-Ho 

 deposits, viz., the conoidal, the elongate-conoidal and the conical, but 

 all are more highly specialized, larger and considerably thicker. The 

 representative of the conoidal type is T. obesa, a shell that seems to come 

 from the common stock of T. theohaldi and T. naticoides but has the 

 spiral sculpture better developed than that of the former and is more 

 globose than either. I have been able to examine only four specimens 

 of this species, but it does not seem to be variable. The elongate- 

 conoidal shell {T. cylindrica) is a very remarkable one, alhed to T. lacvs- 

 tris from the He-Ho deposits, but both more elongate and with the chief 

 spiral ridge of the body-whorl distinctly squamous though without 

 spiniform projections. We collected a good series, which is constant. 

 The conical shell (T. conica) from this basin differs from T. analoga, 

 apart from its greater size and thickness, mainly in the more elaborate 

 nature of its spiral sculpture and especially in the possession of a regular 

 series of subspiniform projections on the body- whorl. Our series is not 

 a large one but the specimens in it are uniform. 



More information is available about the three species of Taia that 

 still live in the Inle Lake than about those that formerly lived at He-Ho 



