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



been recorded from any other definite locality, are also found in swamps, 

 pools and canals in the neighbourhood and have a wide distribution 

 at any rate in Burma. Hydrohioides nassa lacustris occurs with the 

 typical form in this zone only. Probably the pond form of Limnaea 

 andersoniana, of which a dead shell was found floating on the surface, 

 visits it occasionally, but the smaller Limnaeidae of other parts of the 

 lake are scarce if not altogether absent. Succinea indica is found at the 

 margin. We took no specimens of Melania or of any Pelecypod. 



Fish. — Most or all of the fish of the Central Eegion of the lake 

 wander as far as the Marginal Zone occasionally, but its characteristic 

 species, which rarely or never visit the Central Eegion, are the eels 

 Amphipnous cuchia and Monopferus albus, the cat-fish Clarias hatrachus 

 and the minute but brilliantly coloured C^prinid Microrasbora erythro- 

 mieron. With the exception of the last, these are mud-haunting species 

 of wide geographical range that flourish in marshes, rice-fields, ditches, 

 canals and slow streams. M. erytlwomicron is, however, a surface or 

 mid-water fish that conceals itself under floating vegetation. It is only 

 known from the Inle Lake and from other parts of the Inle basin, in 

 which it is, to judge from its frequent occurrence in the dried whitebait 

 sold in the Intha bazaars, by no means uncommon. A single specimen 

 of the peculiar little eel Chaudhuria caudata was taken in this zone. 



Reptiles. — The tortoise Cyclemys dhor shanensis, only known from 

 the Inle system, is not uncommon at the edge of the lake. 



Animal Life in the Inteemediate Zone. 



There are few species confined to this zone, which is naturally a meet- 

 ing-place for those of the Central Region and those of the Marginal 

 Zone. Perhaps the most characteristic feature is the rich growth of 

 sponges, mainly Ephydafia fluviatilis var. intha. 



Sponges. — The Ephydatia is very common on weeds and Spongilla 

 lacustris var. proliferens occurs. 



Hydkozoa. — Numerous specimens of Hydra vulgaris were found 

 amidst a growth of Hislopia on a post in this region. 



Annelida. — Minute free-living Oligochaetes of the family Naididae 

 are common among weeds and Polyzoa, but the only specimens collect- 

 ed were from the canals of Ephydatia. They represent three species of 

 the genus Chaetogaster, one of which has recently been described 

 from freshwater sponges in Japan, w^hile another was originally found in 

 the same organisms in Calcutta, the third being Palaearctic and often 

 quasi-parasitic on Limnaea. 



Polyzoa. — The house-posts of fishing-huts erected in this zone are 

 covered with a growth of Hislopia lacustris, which also occurs very 

 commonly on the shells of living molluscs of the genera Hydrohioides 

 and Taia. We found, on the stem of a plant, a single colony of H. 

 m.alayensis, an allied species described from a small lake in the Siamese 

 Malay States and also common in the River Hughli at Calcutta. 



Decapod Ceustacea. — Probably the only Decapod Crustacea that 

 live in this zone are the same as those found in the Central Region, 

 namely Potamon Qcanthicurri and Caridina annandalei. 



