DISTEIBUTIOW OP IFDIAN FRESHWATER EISHES. 571 



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

 were streams or ponds of fresh water along which these fishes 

 went. 0. gachua is first met with at Guadur, also on the hills of 

 Beluchistan and Afghanistan ; it extends through the Indian and 

 Gey Ion 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. micro-peltes 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 waters of the islands of the 

 Malay archipelago. The allied genus Channa is also found in 

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

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

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

 phibious Foly acanthus signatiis is only found in Ceylon and 

 Java. 



The delicate little HajplocMlus panchacc 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 freshwater 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 Siluridae 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. Dusswnieri 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 

 Thynnichthys 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 



