358 BASIN OF THE LOWER ORINOCO. 



19i. I noticed on the north-west extremity of the basin 

 the West Indies, that the secondary formations dip towards 

 S.E. ; along the coast of Venezuela, rocks of gneiss and primi- 

 tive mica-slate dip to north-west. The basalts, amygdaloids, 

 and trachytes, which are often surmounted by tertiary lime- 

 stones, appear only towards the eastern and western banks. 



III. THE BASIN OP THE LOWER ORINOCO, OR THE 

 PLAINS or VENEZUELA. This basin, like the plains of Lom- 

 bardy, is open to the east. Its limits are the littoral chain 

 of Venezuela on the north, the eastern Cordillera of New 

 Grenada on the west, and the Sierra Parime on the south ; 

 but as the latter group extends on the west only to the 

 meridian of the cataracts of Maypures (long. 70 37'), there 

 remains an opening or land-strait, running from north to 

 south, by which the Llanos of Venezuela communicate with 

 the basin of the Amazon and the Rio Negro. We must 

 distinguish between the basin of the Lower Orinoco, pro- 

 perly so called (north of that river and the Eio Apure), and 

 the plains of Meta and Guaviare. The latter occupy the 

 space between the mountains of Parime and New Gre- 

 nada. The two parts of this basin have an opposite direc- 

 tion ; but being alike covered with gramina, they are usually 

 comprehended in the country under the same denomination. 

 Those Llanos extend, in the form of an arch, from the mouth 

 of the Orinoco, by San Fernando de Apure, to the confluence 

 of the Eio Caguan with the Jupura, consequently along a 

 length of more than 360 leagues. 



(a) Part of the lasin of Venezuela running from east to 

 west. The general slope is eastward, and the mean height 

 from 40 to 50 toises. The western bank of that great sea 

 of verdure (mar de yerbas) is formed by a group of moun- 

 tains, several of which equal or exceed in height the Peak of 

 Teneriife and Mont Blanc. Of this number are the Paramos 

 del Almorzadero, Cacota, Laura, Porquera, Mucuchies, 

 Timotes, and Las Eosas. The height of the northern and 

 southern banks is generally less than 500 or 600 toises. It 

 is somewhat extraordinary that the maximum of the depres- 

 sion of the basin is not in its centre, but on its southern 

 limit, at the Sierra Parime. It is only between the meridians 



