432 



mountainous land lies towards the east, at the 

 back of the declivity of the Andes. It is not a 

 widening of the eastern chain itself, but rather 

 of the counter-forts of small height that follow 

 the foot of the Andes like a penumbra, filling 

 the whole space between the Beni and the Pa- 

 ehitca. A chain of hills bounds the eastern 

 bank of the Beni to 8° of latitude ; for, accord- 

 ing to the very exact information I received 

 from father Nacisso Gilbar, the rivers Coanache 

 and Magua, tributaries of the Ucayali (flowing 

 in the 6° and 7° latitude), come from a moun- 

 tainous land between the Ucayali and the Javari. 

 The existence of this land in so eastern a longi- 

 tude (probably long. 74°), is so much more re- 

 markable, as we find at four degrees of latitude 

 further north, neither a rock nor a hill on the 

 east of Xeberos, or the mouth of the Huallaga 

 (long. 77° 56'). 



We have just seen that the counter-fort of 

 Beni, a sort of lateral branch, loses itself towards 

 8° of latitude ; the chain between the Ucayali 

 and the Huallaga terminates at the parallel of 

 7° in joining, on the west of Lamas, the chain of 

 Chachapayas, stretching between the Huallaga 

 and the Amazon. Finally, the latter chain, 

 which we have also designated by the name of 

 central, after having formed the rapids and ca- 

 taracts of the Amazon, between Tomependa and 

 San Borja, turns towards the north-north-west, 



