288 
LINES OE MOUNTAIN ELDGES. 
dilleras being altogether in disuse as applied to the chains 
01 mountains extending from the eastern gulf of Maracaibo 
o the promontory of Paria, we shall continue to desio'iiate 
those chains (stretching from west to east) by the nances of 
Idtoral chain,” or “ coast-chain of Venezuela.” 
Of the three insulated groups of mountains, that is to 
say those which are not branches of the Cordillera of the 
Andes and its continuation towards the shore of Venezuela, 
one IS on the north, and the other two on the west of the 
Andes : that on the north is the Sierra Kevada do Santa 
fo (S’® o^’ers are the Sierra de la Parinie, between 
4 and 8 of north latitude, and the mountains of Brazil, 
between 15 and 28 south latitude. This singular distri- 
hiition of great inequalities of soil jiroduces three plains 
or basins, comprising a surface of 420,(100 square leaciiies, or 
foiir-htths of all South America, east of the Andes. Between 
the coast-chain of Venezuela and the group of the Parinie, 
the plains of the Apure and the Lower Orinoco extend ; 
between the group of Parinie and the Brazil mountains are 
the plains of the Amazon, of the Eio Negro, and the Madeira, 
and between the groups of Brazil and the southern extremity 
of the continent are the plains of Eio de la Plata, and cif 
Patagonia. As the group of the Parinie in tipanish Guiana, 
and ol the Brazil mountams (or of Minas Geraes and Goyaz), 
do not join the Cordillera of tlie Andes of New Grenada and 
Cpper 1 erii towards the west, the three plains of the Lower 
Orinoeo, the Amazon, and the Eio de la Plata, are connected 
by land-straits of considerable breadth. These straits are 
also plains stretching from north to south, and traversed 
by ridges imperceptible to the eye, but forming “divortia 
aqiiarum. These ridges (and this remarkable phenomenon 
as hriiierto escaped the attention of geologists) are situ- 
ated betiyeen 2° and 3° north latitude, and 16'^ and 18=’ 
south latitude. The first ridge forms the partition of the 
waters which fiiU into the Lower Orinoco on the north-east, 
and into the Eio Aegro and the Amazon on the south and 
south-east ; the second ridge divides the tributary streams 
ot the right bank of the Amazon and the llio dt* hi Plata. 
lese ndges, of which the existence is only manifested, as 
111 V olliyma, by the course of the waters, are parallel with 
the coast-chaui of Venezuela ; they present, as it were, two. 
