eigenmann: fresh water fishes. 311 



and Rio PatiaMira in Colombia, the Esmeralda, Daule, Guayas and Tumbey 

 in Ecuador, and the Chia, Jequetepec, Santa, Rimac and others in Peru. 

 None of those in Colombia have been examined, and but few of those 

 in Peru. 



The headwaters of these rivers are all near the headwaters of At- 

 lantic slope streams. In northern Ecuador and in Peru they are separated 

 by a high ridge. Of special interest are the San Juan and Patia. In 

 northern Peru there are four main chains of the Cordilleras, besides the 

 coast range. The valleys between these are occupied by large rivers, the 

 Ucayale, Huallaga and Maranon, all ultimately draining into the Amazon. 

 In Ecuador there are two very high chains with frequent cross-ridges divid- 

 ing the longitudinal trough into parks or highland basins, some drained 

 to the east and some to the west. 



In Colombia there are again four chains. The eastern one divides to- 

 wards the north, one branch sweeping around to the east toward Caracas 

 and Trinidad, another branch extending to the coast west of Lake Maracaibo. 

 Between this and the central chain flows the Magdalena which occupies 

 much the same position in regard to the Cordilleras that the Ucayale or 

 Huallaga occupies, but empties into the Caribbean Sea. Between the 

 central and western Cordilleras flows the Cauca, a large tributary of the 

 Magdalena. South of the Cauca the Rio Patia has cut through the west- 

 ern Cordilleras, its headwaters coming from the same trough in which 

 the Cauca flows. 



Of still higher interest is the trough between the western Cordillera 

 and the coast or border Cordillera. 



Sievers, p. 478, states that the west Cordillera of Ecuador is younger 

 than the central Cordillera, and the coast range still younger. Its height 

 varies from 800-1800 m. A longitudinal valley separates the coast 

 range from the western Cordillera. In this flows the Atrato towards the 

 north, emptying into the gulf of Darien and the San Juan towards the 

 south, emptying into the Pacific Ocean. The water-shed separating the 

 two scarcely reaches a height of 100 m. above sea-level, the distance of 

 the height of land above their headwaters is naturally much less than this.'' 

 I shall return to these rivers again. 



The fauna of this province, so far as known, is very poor. In con- 



' A gentleman, for several years a missionary in Colombia, has informed me that the Indians of 

 the Atrato have a legendary belief in a former interoceanic connection through the Atrato valley. 



