
1922.] Fauna of the Fresh and Brackish Waters of India. 529 
groups unknown, though doubtless existing as rarities, in 
adjacent seas. I may mention in particular the primitive sea- 
anemone Hdwardsia tinctrix, the congeners of which are mainly 
found in northern regions but also occur in the extreme south. 
The direct effects of a lowering of the salinity, and, therefore, 
of the specific gravity, of the water on a medusa (Acromitus 
rabanchatu) common in the lake and also in the Bay of Bengal, 
have been observed, while much other bionomical informa- 
tion of a like nature has been obtained. The report when 
complete will be the first detailed account of the fauna of any 
tropical area of brackish water. We hope to finish it next 
ear. 
The chief object of my visit to the Far East in 1915 and 
1916 was to obtain material for a comparison between the 
fauna of the Chilka Lake and of other bodies of water of low 
salinity in India on the one hand, and that of three lakes 
situated further East in Asia. These lakes were Lake Biwa on 
the Main Island of Japan, the Tai-Hu in the Kiangsu province 
of China and the Talé Sap in Peninsular Siam. The last of 
these resembles the Chilka Lake very closely in many respects, 
while the Tai-Hu is situated not far from the coast and has 
a large rine element in its fauna; but Lake Biwa is a 
typical alpine lake. 
he volume in the Memoirs of the Asiatic Society of 
Bengal, although it does not deal directly with the Indian 
fauna, has, therefore, an important indirect connection with 
our present subject. Like that on the Chilka Lake it contains 
zoological papers by many specialists. 
n a separate paper on the fauna of Lake Biwa, to be 
published shortly in the Annotationes Zoologicae Japonenses', 
I have compared the fauna of that lake with the fauna of 
several other inland lakes in India and other parts of Asia. 
Another volume devoted primarily to an aquatic fauna 
living on and near the Indian frontiers is volume XVIII of the 
Records of the Indian Museum, which is concerned with the 
isolated basin of Seistan in the eastern part of the Persian 
desert and with certain districts of British Baluchistan. The 
investigations carried out in these countries by Dr. 8. W. Kemp 
and myself in the winter of 1918-1919 have provided much 
interesting material for comparative study. Although Seistan 
is an inland country and has had no communication with the 
sea since very ancient times, its lake (the Hamun-i-Helmund) 
and watercourses have this much in common with the Chilka 
Lake, that very little of their water is quite fresh. Its salinity, 
however, is due to purely local causes and the salts it contains 

! Now published in Annot. Zool. Jap., X (1922). 
