EIGENMANN I FRESH WATER FISHES. 



351 



Species of the Upper Parana, Lower Parana, La Plata and Rio Grande do Sul. 



The Parana below the falls to Buenos Aires has been made known by- 

 Valenciennes, Gunther, Perugia, Berg and La Hille. 



At this place may also be considered the fauna of that part of Rio 

 Grande do Sul draining eastward. The fauna of this area is more distinct 

 from that of the La Plata than the Paraguayan is from the Amazonian, 

 only about 46 per cent, of its fishes being identical with species occurring 

 in the La Plata. Its affinities are, however, with the La Plata rather than 

 with the coastwise streams north of Rio de Janeiro, only about 30 per 

 cent, of its fauna being identical with that of the northern rivers. 



There are known in the region under consideration 170 species which 

 may safely be considered to be less than one-half of the total number of 

 species inhabiting it. Of these, 64 species are also found in the Paraguay, 

 50, or a little over 29 per cent, are of wide distribution, having been 

 taken in the Amazon. Thirty-four species are common to this region and 

 southeast Brazil. Of these, 15 are included in the 49 recorded from the 

 Amazon, leaving 19 common to the two regions. This number gives us 

 a hint as to the extent to which southeast Brazil has contributed to the 

 La Plata, or the La Plata to the latter. 



