eigenmann: fresh water fishes. 329 



tributed to the Amazonian fauna when the latter was formed and received 

 in turn new Amazonian types. 



The fauna of eastern Brazil differs much more from that of the Ama- 

 zon than does that of the equally old Guiana. By eastern Brazil is here 

 understood the northeastern part of this old land-mass, i.e., the territory 

 north of the Parana basin and between the eastern watershed of the To- 

 cantins and the coast south from Cape San Roque to the Iguape. The 

 entire territory has an average height of about 2,000 feet. North of the 

 Parahyba it is in the form of two wide terraces, besides the coastal plain. 

 The western terrace is occupied by the San Francisco basin ; it is sepa- 

 rated from the eastern narrower terrace by a series of Serras beginning 

 with the Serra da Tuila, near the mouth of the San Francisco, and end- 

 ing in the Serra do Espinhaco near Rio de Janeiro. In these Serras and 

 the table-land or middle, terrace to the east of them are the sources and 

 middle courses of a number of rivers with a general west to east course. 



This middle terrace is bordered on the east by the coast ranges ex- 

 tending from the Parahyba north. Through it all of the rivers of the 

 region have broken their path and in it all of them have extensive falls. 



These streams with the tributaries and localities where collections have 

 been made are: (i) Rio Paraguassu, emptying at Bahia ; (2) Rio de Con- 

 tas ; (3) Rios Jundiahe, Salsa, Pardo and Jequitinhonha (with its tributary 

 Arrasuahy) emptying at Cannavierias ; (4) Rio Mucury on which are 

 located Porto Alegre and Santa Clara; (5) Rio de San Matheos ; (6) Rio 

 Doce and its tributary Rio San Antonio; (7) Rio Quenda, emptying at 

 Santa Cruz ; (8) Rio Itabapuana. 



Farther south we have : (9) Rio Parahyba with its tributaries Piabanha, 

 Pirahy, Muriahe, Pampa and Preto (Campos; Juiz de Fora ; Mendez ; 

 Taubate) ; (10) Macahe ; (11) Rio de Janeiro; (12) Santos and Alto da 

 Serra; (13) Iguape. 



The Parahyba, Santos and Iguape are opposite to the Parana basin, all the 

 others to the San Francisco. The trend of the Parahyba is different from 

 that of the coastwise streams to the north of it. It flows first southwest, 

 then northeast parallel with the coast range and between it and the Serra 

 de Mantegueira. Von Ihering has suggested that the peculiar trend of 

 the upper course of the Parahyba and some of its tributaries indicates that 

 these were formerly tributaries of the Rio Tiete and were captured from it 

 by the Parahyba. A partial comparison of the faunas of the Tiete and 



