ElGENMANN : COLLECTIONS OF FlSHES FROM PARAGUAY. Ill 



10 kilometers long in another part of the isthmus, but on account of 

 the small amount of trade it was never completed. This would con- 

 nect Montevideo and Para by a continental waterway 8,300 kilometers 

 long. In the near future it is probable that railways will take the 

 place of the canal. There are many places on the edge of the pla- 

 teau, farther to the east, where a simple cut of a few meters would 

 connect the tributaries of the Amazon with those of the Paraguay, 

 transforming eastern Brazil into an island. There is a space of but 

 100 meters between the Estivado, a small tributary of the Tapajoz, 

 and the Tombador, which empties into the Cuyaba." 



In 1 89 1 2 I called attention to the great similarity of the faunae of 

 the La Plata and the Amazons. The former was at that time known 

 to differ from the latter by negative characters only. At the same 

 time I called attention to the radical difference between the fauna of 

 the La Plata and the Amazons and the fauna of the coastal streams 

 that empty into the Atlantic between these two great rivers. 



Every additional collection from the Paraguay, and indeed from 

 the entire system of the La Plata, tends to emphasize the similarity 

 of its fauna with that of the Amazons. 



The interest that centers in the Paraguayan fauna becomes apparent 

 from the above considerations. It is through the basin of the Para- 

 guay that the La Plata has probably received its Amazonian character. 

 For this reason accurate representations of the members of the fauna 

 are greatly desired and an attempt has been made to supply these in 

 the photographs of a number of actual Paraguayan specimens which 

 accompany this paper. 



The basin of the Paraguay approaches in area the basin of the Ohio 

 plus that portion of the basin of the Mississippi north of the entrance 

 of the Ohio and exclusive of the basin of the Missouri River. The 

 area then is very large. The means of communication for the most 

 part are primitive, and probably but a fraction of the fauna is known. 

 Two hundred and fifty-four species have been recorded from this 

 basin. The regions that will probably yield the richest rewards in 

 the future are the mountain brooks and pools of central Paraguay, the 

 ponds of the Chaco, and the mountain sources of the Pilcomayo. In 

 the Proceedings of the Philadelphia Academy of Sciences for 1903, 

 pp. 497-537, Eigenmann and Kennedy reported on a collection of 

 fishes made by Professor J. Daniel Anisits in the basin of the Paraguay. 



* Proc. a S. Nat. A/its., Vol. XIV., pp. I et seq., 1891. 



