for the year 1016-17 . ix 



Dr. Chaiidliuri visited Mysore primarily in order to attend the 

 fourth meeting of the Indian Science Congress at Bangalore as re- 

 presentative of the Zoological Survey, but he 

 isi ysore. ^^^^ examined, so far as an outbreak of plague 



permitted him, the fish of certain large tanks in the neighbourhood 

 of Seringapatam. A century ago the distinguished ichthyologist 

 Buchanan-Hamilton obtained in these tanks several fish that had 

 not been rediscovered. Dr. Chaudhuri made an interesting collection, 

 which stress of other work has rendered it impossible for him to 

 work out as yet. It contains several of the lost fish and also in 

 all probability species new to science. 



The last tour undertaken by the department in the financial year 

 1916-17, by Dr. F. H. Gravely and myself, went further afield than 

 anv other. Its object was to mvestigate the 

 ShlnSta'tes^.^' ^''"*''"'" fauna of a lake on the Shan Plateau, the fauna 

 of which is a remarkably isolated one. With the 

 assistance of Mr. G. C. B. Stirling, CLE., Superintendent of the 

 Southern Shan States, and Mr. C. E. Browne, I.S.O., Political Adviser 

 in Yawnghwe, the Inle Lake in that State was selected as being 

 readily accessible and at the same time practically unknown from 

 a zoological point of view ; the only animals previously reported from 

 it being a series of fish collected by the late Mr. E. W. Gates and 

 described by Dr. G. A. Boulenger of the British Museum. 



The lake is of great interest from a purely limnological point of 

 view and seems to be the last survivor of a network of water-basins 

 and small streams that occupied, at a period geologically by no 

 means' remote, a very considerable area on the Shan Plateau. It 

 belongs to the type of lake that has been called " solution lakes," 

 that is to say, its basin has been dissolved out of limestone by the 

 action of water. Like most shallow lakes it seems to be gradually 

 filling up. This is due both to the deposition of the silt brought 

 down from surrounding hills by streams, and to the growth and 

 decay of aquatic and marginal vegetation. Curious floating islands 

 (Plate B) comparable on a small scale to the sudd of the Nile are 

 constantly being formed round the edge by the latter agency. The 

 lake is now about 14 miles long and nowhere more than 12 feet 

 deep. Its soft muddy bottom bears a luxuriant growth of water- 

 weeds and its water, which is strongly charged with lime, is remark- 

 able for its glassy clearness. 



The fauna has little relationship with any other yet known, but 

 probably will be found to be similar in some respects to that of the 

 upper Sal ween. Fortunately for the investigator who has limited 

 time at his disposal, it is, like that of the Mutlah, rich in individuals, 

 but poor in species. So far, only a preliminary examination has 

 been possible, but this has already shown that the fish include 

 representatives of a considerable number of new species and of three 

 new genera. One of these is a minute eel, so difTerent from any 

 form hitherto described that it must be regarded as the type of a 

 new family. It is distinguished from aU other living eels at present 



