92 Contributions to Indian Malacology. [No. 2, 



In the Tsagain hills, west of the Irawady, opposite Ava, I obtained 

 two forms, one bluntly angled at the periphery and approaching H. 

 Oldham /, in which however the spire is lower and the umbilicus more 

 open. The sculpture, form of the whorls and of the mouth, (which is 

 rounded with connivent margins and expanded throughout,) and the 

 angulation of the periphery, are precisely similar to the same characters 

 in my specimens of H. tapeina : the umbilicus is slightly broader, and 

 the spire lower, sometimes as flat as in Akoutongensis. The dimensions 

 are 15J and 14 millem. in the two diameters ; height 6. The other 

 form is extremely sharply keeled and lenticular, with an angulate 

 lunate mouth, and a narrower umbilicus than the last, or even than the 

 Cherra tapeina, but it has the same simple sculpture, differing in this 

 from the Shan hills form, which it otherwise resembles. It mea- 

 sures 17J millem. by 16, and 9 in height. 



The next locality to the south in the Irawady valley at which I 

 obtained forms of this type was at Thayet Myo. I have already re- 

 ferred to the variety prevailing there, as well as at Prome and Akou- 

 toung. As a rule, the shells are small, thin, horny, and more or less 

 hispid, very variable in the height of the spire, sharply keeled and 

 with very fine, flexous striation. The major diameter is about 10 to 

 12 millem. on an average. 



At Henzada, and in its neighbourhood, another form prevails. It 

 is also met with at Akoutoung, but is rare, and it passes into the 

 flatter form there prevailing. The Henzada shell has a much higher 

 spire with veiy convex sides, and is, in fact, subcampanulate, the 

 base, on the other hand, being flattened. It is sharply keeled, quite 

 as sharply as the Akoutoung form, but it has the sculpture rather of 

 II. tapeina than of rotatoria, and the epidermis, instead of being sub- 

 hispid as in the latter shell, is merely granulate. A form, interme- 

 diate both in height of spire and in sculpture between the Henzada 

 and Akoutoung varieties, was found in the Arakan hills, between 

 Prome and Tongoop. 



In the Bassein district, all the shells of this type are much the 

 same. They have a sharp keel, moderate spire with convex sides, 

 obtuse apex, and but little convexity beneath. They possess a granu- 

 late epidermis and the sculpture of H. tapeina. 



The specimens with the highest spires, from Henzada, approximate 



