DISTRIBUTION OY INDIAN FRESKWATEH FISHES. 571 



these islands together and to the mainland, while over this land 

 were streams or ponds of fresh water along w^iich these fishes 

 went. O. gaclma is first met with at Guadur, also on the hills of 

 Beluchistan and Afghanistan ; it extends through the Indian and 

 Ceylon subregions, Assam, and Burma ; while, as I have formerly- 

 remarked, it is common in the streams at the Andaman Islands. 

 I can only account for their presence in such a spot by the same 

 theory of a former land-connexion with the mainland ; the dis- 

 tance is too far for any accidental cause to have occasioned its 

 presence there. 



O. micropeltes is present in the rivers of Canara and Malabar, 

 absent from the plains of India and Burma, reappearing in Siam ; 

 and is distributed through the fresh w^aters of the islands of the 

 Malay archipelago. The allied genus Clianna is also found in 

 Ceylon, but disappears between that island and China. The per- 

 coid genus FristoJepis exists at the base of the Malabar hills, but 

 is not found elsewhere in India, reappearing in Burma. The am- 

 phibious Foly acanthus signatus is only found in Ceylon and 

 Java. 



The delicate little Haplochilus panchax is distributed in the 

 fresh waters of the Andaman Islands, and is likewise found through 

 the Ceylonese and Hindustan subregions, also in Burma and the 

 islands of the Malay archipelago. 



But the Nicobars give us another freshw^ater fish which is ab- 

 sent from the islands of the Malay archipelago, but present on 

 the mainland of India, Burma, and Siam, whence it has probably 

 spread ; it is the little Nuria danrica, of which Mr. Ball brought 

 several examples from the Nicobars. 



Amongst the Siluridse we find somewhat the same distribution 

 may occur. Clarias magur is found throughout India, Burma, 

 and the Malay archipelago, C. Teysmanni in Ceylon and Java, 

 and C. Dussumieri along the coasts of India and the islands 

 of the Malay archipelago, these last two, so far as is known, 

 being absent from the intervening districts. The Cyprinoid 

 ThynnicJithys is also a resident only in the Deccan, Kistna, and 

 Godavery rivers in India, reappearing in the islands of the Malay 

 archipelago. 



These examples of distribution are not peculiar to fishes, but 

 are seen in other divisions of the animal kingdom, and would seem 

 to point out that there must at a former period have existed a 

 land communication between Malabar and Ceylon and the Malay 



