96 DR. NELSON ANNANDALE ON THE 



Lake on the east coast of India, but ratlier with shallow inland fresli- 

 water Likes such a-s the Tai Hu in the Iviangsu Province of China and 

 possibly the Tonle Sap in Cambodia. Comparison with the former is 

 particularly apposite, because there is evidence both geographical and 

 faunistic, that it was connected with the sea at no vevy distant date 

 and has been isolated by the rapid growth of the Yangtse delta. 



IL The Fauna of the Outer Lake and of the 

 Connecting Channels. 



The change of fauna as one proceeds southwards from Pak 

 Payun is remarkable and immediate. We have to deal no longer witli 

 freshwater animals, but with marine and estuarine types, some of 

 which are extremely characteristic of marine lakes. 



Mammals, The only aquatic mammal that 1 have seen in the 

 Tale Sap is a small Cetacean that inhabits, or inhabited, the main con- 

 necting channel at certain seasons of the year. I saw a small school of 

 this porpoise near the uppsr eti 1 of the cliannel in March and April, 

 189y, and again in December, 1901 ; but though it then appeared to be 

 well known to the villagers (who refused to assist in the capture of 

 specimens for any reward that we were able to offer), I was unable 

 to obtain any information about it in January and February, 1916. The 

 species is probably an interesting one and is almost certainly unknown 

 to science. It is remarkable for its small size, long narrow snout and 

 bright brown colour 



Other Vertebrates. Several species of sea snake enter the mouth 

 of the Tale Sap freel}' and are caught in the fishermen's nets near 

 Singgora. Tiie commonest are Eithi/dris hanlirkldi and Enlii/drina 

 valak'idieii, Chersijdrus tiramdatas is also caught in the nets, and 

 Cerberus rhijnchops is common among stones round the shores of 

 Koh Yaw. 



One of the two species of 'Rdna found at the elge of the lake in 

 the neighbourhood of Lampam (7i'. cancrirora) is also common in the 

 same position near Singgora and does not hesitate to enter brackish 

 and even salt water. 



Theie is a wealth of fish at Singgora, where large numbers of a 

 great varietj' of species are caught at different seasons, mainly in 



JOL'ltX. NAT. H18T. SOC. S^IAM. 



