454 



mouth of theRioSimu andthesmall town of Tolu, 

 or even the calcareous heights of Turbaco and 

 Popa, near Carthagena, may not be regarded as 

 the most northern prolongation of this second 

 branch. A third, advances towards the gulph 

 of Uraba* or Darien, between the Rio San 

 Jorge and the Atrato. It is linked towards the 

 south, with the Alto del f^iento, or Sierra de 

 Abide, and is rapidly lost, in advancing as far 

 as the parallel of 8°. Finally, the fourth 

 branch of the Andes of Antioquia, placed on the 

 west of Zitara and the Rio Atrato, undergoes, 

 long before it enters the isthmus of Panama, such 

 a depression, that between the gulph of Cupica, 

 and the embarcadere of the Rio Naipipi, we find 

 only a plain -f* across which M. Gogueneche has 

 projected a canal of junction of the two seas. 

 It would be interesting to know the configura- 

 tion of the soil between cape Garachine, or 

 gulph of St. Miguel, and cape Tiburon, above 

 all, towards the source of the Rio Tuyra and 

 Chucunaque, or Chucunque, in order to de- 

 termine with precision where the mountains 

 of the isthmus of Panama begin to rise, moun- 

 tains of which the elevation does not appear to 

 be above 100 toises high. The interior of Dar- 



* See above, Vol. vi, p. 331 , and Semanario de Bogota* 

 Tom. ii, p. 83. 

 t Vol. vi, p. 256. 



