587 



stone leaning in a concave position towards the 

 north *, on the transition slates of Malpasso, 

 and on the south, on the gneiss granite of Pa- 

 rime. As the gypsum often immediately covers 

 the sandstone of Calabozo, which appeared to 

 me cm the spot, to be identical with our soil of 

 red sandstone, I am uncertain of the age of its 

 formation. The secondary rocks of the Llanos 

 of Cumana, Barcelona, and Caraefcas, occupy a 

 space of more than 5000 square leagues. Their 

 continuity is so much the more remarkable, as 

 they appear to be wanting, at least on the east 

 of lihe meridian of Porto Cabello (70° 37') in 

 the whole basin of the Amazon, unless they are 

 covered by granitic sands. The causes which 

 have favoured the accumulation of calcareous 

 matter in the eastern region of the chain of the 

 shore in the Llanos of Venezuela (from 101° to 

 8° north), have not acted nearer the equator, in 

 the groupe of the mountains of Parime, and in 

 the plains of the Rio Negro and the Amazon (lat. 

 8° north, to 1° south). The latter plains how- 

 ever, furnish some shelves of fragmented rocks, 

 on the south-west of San Fernando de Atabapo, 

 as well as towards the south-east, in the lower 

 course of the Rio Negro and the Rio Branco. I 

 saw a sandstone in the plains of Jacn de Braca- 

 inoros which alternates at the same time with 



* Muldenformige Lagerun£. 



