455 



four is not more unknown to geographers, than 

 the humid, insalubrious land, covered with 

 thick forests, which extends on the north-west 

 of Betoi and the confluence of Bevara with the 

 Atrato, towards the isthmus of Panama. All 

 that we hitherto know positively, is, that be- 

 tween Cupica and the left bank of the Atrato, 

 there is either a land- strait, or a total absence 

 of the Cordillera. The mountains of the isth- 

 mus of Panama may, by their direction and 

 their geographical position, be considered as a 

 continuation of the mountains of Antioquia and 

 Choco ; but on the west of Bas-Atrato, there 

 scarcely exists a ridge in the plain. We do not 

 find in this country a groupe of interposed 

 mountains like that which indubitably links 

 (between Barquesimeto, Nirgua, and Valencia) 

 the eastern chain of New Grenada (that of 

 Suma Paz and the Sierra Nevada de Merida) to 

 the Cordillera of the shore of Venezuela. 



In order the better to impress on the memory 

 the results of my laborious researches on the 

 structure and configuration of the Andes, I 

 shall collect them in the form of a table, be- 

 ginning with the most southern part of the 

 New Continent. We shall see that the Cor- 

 dillera of the Andes, considered in its whole 

 extent, from the rocky breaker of Diego Ra- 

 mirez, as far as the isthmus of Panama, is 

 sometimes ramified into chains more or less 



