330 PATAGONIAN EXPEDITIONS : ZOOLOGY. 



Parahyba is possible, and will be given in the lists of species of this 

 region. 



The San Francisco, which occupies the western terrace and flows at 

 right angles to the coastwise streams to near the 9th degree of latitude, 

 where it also turns to the east, is the largest river. It has a length of 

 2000 km. and a basin of 652,000 square kilometers. Its origin is at an 

 elevation of 1200 m., and about its headwaters "are some of the highest 

 elevations in Brazil." It has an upper fall of 15 m. near Pirapora and a 

 lower fall of 80 m. at Paulo Alfonso. 



The fish fauna of this area has become known, first, through the work of 

 Liitken, who has published an excellent account of the fishes of the Rio 

 das Velhas, an upper tributary of the Rio San Francisco ; second, through 

 Steindachner, who has published accounts of the fishes of the coastwise 

 streams, Steindachner basing his account on the very extensive collections 

 made in the lower and upper courses of all the streams by Agassiz and 

 his assistants, and through Eigenmann who has written on the fishes at 

 Taubate and the Rio Tiete. 



The fauna of this area as a whole is distinguished by the absence of 

 certain Amazonian forms. It is of increased interest because many genera 

 absent from this area are found in the La Plata basin as well as in the 

 Amazon basin, having evidently reached the La Plata through the interior 

 waterway rather than from stream to stream along the coast. 



8. The San Franciscan Province. 



The Rio San Francisco being nearer the Amazonian Province has a 

 larger proportion of Amazonian genera than the streams south of Bahia. 

 Notably the Serrasalmoninae and the Gymnotidae, present in the San 

 Francisco, are not recorded from the coast streams. It forms a faunal prov- 

 ince distinct from the rest of the area to the east. 



The following species have been recorded from the Rio San Francisco 

 and its tributaries, the Rio Preto and Rio das Velhas, and the Rio Cipo, a 

 tributary of the Velhas. 



Explanation of Markings Used. 

 L Also found in the La Plata Basin. 

 A Also found in the Amazons. 

 * Species peculiar to the San Francisco. 



