i68 Memoirs of the Indian Museum. [Vor,. V, 



as we know, an exclusively Indian and Burmese snake, occurring on both sides of the 

 Peninsula and on the coast of Tenasserim. It particularly affects brackish water 

 and occurs in the Gangetic delta. 



Thus we may say that the snakes of the Chilka Lake represent an essentially 

 estuarine element in its fauna and one of wide, or fairly wide, dispersion in the 

 Oriental Region. 



Crocodilus palustris has a range similar to but even wider than that of Cerberus 

 rhynchops, and is more of an up-country animal. Gavialis gangeticus , on the other 

 hand, is entirely confined on the east coast of India to river-systems that open into 

 the upper part of the Bay of Bengal; it is probably not found, even on this coast, 

 further south than the Chilka Lake. On the western side of India it occurs, like 

 Orcaella brevirostris , in the Indus. 



Of the Chelonia of the lake the two Chelonidae are widely-distributed marine 

 species, while the Trionychid is an essentially limnic form somewhat restricted in range 

 — -a local race, confined to the river-systems of the Mahanaddi and the Godavari and 

 a few adjacent valleys, of a species that occurs all over Peninsular India, the Indo- 

 Gangetic plain, the greater part of Burma and the plains of Ceylon. Its genus, 

 which is monotypic, is not found, except in Ceylon, beyond the limits of the Indian 

 Empire. 



Rana cyanophlyctis , the only frog or toad found in the lake, occurs over an area 

 extending from Arabia to the Malay Peninsula, and is known to avoid brackish water 

 less than most of its congeners. 



Considered as a whole, the herpetological fauna of the Chilka Lake may there- 

 fore be regarded as an essentially estuarine one, in which most of the species are of 

 wide distribution; there is no endemic element. In so far as it is peculiarly Indian, 

 it is, as might be expected, Peninsular as opposed to Indo-Gangetic. 1 



1 A word may be said as to the terrestrial reptiles and frogs that haunt the margins of the Chilka 

 Lake. The most conspicuous is the Indian Monitor (Varanus bengalensis) , which was seen on several 

 occasions on the stony beach of Barkuda Island, but is much more often to be observed, in Orissa and 

 Ganjam, in holes in the walls of wells or among the trunks of fallen trees. It does not wander over the 

 mud-flats, as V. salvator and V. nebulosus do in some parts of the Malay Peninsula, and probably obtains 

 little if any of its food from the lake. A small skink (Lygosoma pundatum) was found under dead 

 Pandanus-leaves at the edge of the lake near Barkul. Its stomach contained amphipodous Crustacea of 

 the group Gammaridea. The same animals are eaten by two species of Gecko {Hemidactylus brookei 

 and H. frenatus) that are abundant among stones and rocks just above the water-level and occur 

 even on the smallest islands in the lake. They also feed largely on the Saldid bug Leptopus assuanensis, 

 which, without being exactly aquatic or even amphibious, is extremely abundant round the lake among 

 rocks and stones in the immediate neighbourhood of water. The four lizards all have a wide range in 

 the plains of India. 



Two burrowing frogs (Rana breviceps and Microhyla ornata) live commonly in holes near the edge of 

 the lake and breed in the rainy season in small pools of rain-water close to the margin ; but we have 

 never seen them enter the lake itself. At Barkul, one night in September, we saw a young Chunam 

 Frog (Rhacophorus maculatus) seated on dead weed at the margin. All these are common frogs in the 

 plains of Peninsular India and the Indo-Gangetic tract. 



