in the Fish Gallery of the Indian Museum. 37 



Besides the fresh-water families, there are a few spe- 

 cies belonging to the under-mentioned marine families 

 that have become adapted to fresh-water in this country, 

 namely : some species of Eels, Herrings, Garpikes, 

 Perches, Gobies, Grey-mullets, Parrot-fishes. These 

 fresh-water immigrants from marine families show us 

 one of the ways in which, in Delta-lands especially, 

 the fresh-water-fauna is being re-inforced from the sea. 



THE GEOGRAPHICAL RELATIONS OF THE MARINE 



FISHES OF INDIA. 



Excluding the estuarine and brackish forms that are 

 passing into the fresh-water-fauna, the marine fishes of 

 India number about 1200 species. Most of them are 

 shore-fishes, a few inhabit the surface-waters of the open 

 sea, and a considerable number live in the great depths. 



The total number of Indian genera is (allowing for 

 different opinions as to the limits of a genus) between 

 330 and 350, of which 54 per cent, are also found in 

 the Atlantic, and chiefly (though not entirely) in tropical 

 or subtropical latitudes of that ocean that embrace the 

 American shores and islands between 40 N. and io° S. 

 and the African shores and islands between the some- 

 what similar parallels. 



Of the 54 per cent, that are common to the Atlantic 

 and the Indian Oceans, half — that is to say, 27 per cent. 

 of the total Indian genera — are also present in the 

 intervening Mediterranean Sea, and a certain number 

 (seventeen genera) that are absent from the Mediterra- 

 nean are present in the intervening Red Sea. Ten more 

 Indian Ocean genera that do not occur in the Atlantic 

 are found in the Mediterranean, so that the number of 

 genera that the Indian Seas have in common with the 

 Atlantic and Mediterranean combined is more than 54 

 per cent, of the total. 



