DISTEIBTJTION OF INDIAN FRESHWATBE FISHES. 573 



manner I have taken the Siluroid genus Euglyptosternu^n from 

 the rivers of the hills of N.E. Assam, from the upper portion of 

 the Jumna at the foot of the Himalayas, and it likewise has been 

 captured in Syria. Barilius, likewise found in East Africa, is 

 distributed to both the Hindustan and Ceylonese subregions, 

 extending into the Himalayas, and also distributed along the 

 western Ghauts to Ceylon. These facts, if they prove any 

 thing, would serve to show that at a former period a commu- 

 nication must have extended up the western coast of India to 

 Sind ; and as we do not find African types represented on the 

 western Grhauts, we may infer that such occurred prior to the 

 communication which took place between Africa and India. If, 

 however, one genus of Carps could pass this way, so could another ; 

 and by this route the means of extension to the Himalayas would 

 have been open ; while by Ceylon and the Andamans fishes might 

 also have extended to the Malay peninsula or the islands of the 

 Malay archipelago. 



I will but briefly remark upon the freshwater fishes of the 

 Himalayan region, as I have elsewhere (" Fishes of Tarkand," 

 P. Z. S. 1876, p. 781) followed out their distribution. We find 

 two great classes, the Tartarian fauna from the Palsearctic region 

 above the Himalayan descending to where it meets the Hindus- 

 tan forms. It must not be forgotten in working out the details 

 of these regions, that vast valleys having a tropical temperature 

 exist in the Himalayas ; and here some Indian forms have found 

 congenial homes. 



The ScMzothoracincB, or hill Barbels, are entirely distinct from 

 any low-country forms, consisting of Carps more or less covered 

 with minute scales or destitute of any ; a membranous sac or slit 

 exists anterior to the anal fin, and is laterally hounded hy a row of 

 vertically -placed scales arranged liJce eave-tiles, and which are con- 

 tinued along the base of the anal fin. The genus Oreinus is that 

 most frequently observed by European visitors to India, as it is 

 found along the sub-Himalayan range : it is possessed of a trans- 

 verse inferior mouth, and a sucker behind the lower jaw, de- 

 monstrating its necessity for some mechanical apparatus to enable 

 it to withstand the force of the hill-torrents. As we ascend to 

 the higher and less precipitous regions we find the gape of the 



from the Malay archipelago ; but it is remarkable that the same species should 

 only be found in two such widely separated localities as the Himalayas and the 

 Ceylonese subregion of India. 



