LINES OF MOUNTAIN EIDGES. 
287 
declivity of the Cordilleras of the Andes. The rising of this 
ridge is so inconsiderable compared to the whole continent, 
that its breadth in the parallel of Cape Saint liocho is 
1400 times greater than the average height of the Andes. 
We distinguish in the mountainous -part oi South America, 
a chain and three groups of mountains, namely, the Cor- 
dillera of the Andes, which the geologist may trace without 
interruption, from Cape Pilares, in the western paid; of the 
Straits of Magellan, to the promontory of Paria, opposite 
the island of Trinidad ; the insulated group of the Sierra 
Nevada de Santa Marta ; the group of the mountains of the 
Orinoco, or of La Parime ; and that ot the mountains of 
Brazil. The Sierra de Santa Marta being nearly in the 
meridian of the Cordilleras of Peru and Aew Grenada, the 
snowy summits descried by navigators in passing the mouth 
of the Eio Magdalena, are commonly mistaken for the 
northern extremity ot the Andes. I shall soon prove that 
the colossal group of the Sierra de Santa Marta is almost 
entirely separate from the mountains of Ocaiia and^ Pam- 
plona, which belong to the eastern Cordillera of New 
Grenada. The hot plains through which runs the Bio 
Cesar, and which extend towards the valley oi L par, separate 
the Sierra Nevada from the Paramo de Cacota, south of 
Pamplona. The ridge which divides the waters between the 
gulf of Alaracaibo and the Bio Magdalena, is in the plain 
on the east of the Laguna Zapatoza. It, on the one hand, 
the Sierra de Santa Marta has been erroneously cousidered 
(on account of its eternal snow, and its longitude) to be a 
eontinuation of the Cordillera oi the Andes, on the other 
hand, the connexion of that same Cordillera with the coast 
mountains of the provinces of Cumana and Caracas, has 
not been recognized. The littoral chain of \ enezuela, of 
which the different ranges form the ^Montana de Paria, the 
isthmus of Araya, the Silla of Caracas, and the^ gneiss- 
granite mountains north and south oi the lake of \ aleucia, 
is joined between Porto Cabello, San Pelipe, and Tocuyo, to 
the Paramos de las Bosas and Niquitao, which form the 
north-east extremity of the Sierra de Merida, and the astern 
Cordillera of the Andes of New Grenada. It is sumcient 
here to mention this connexion, so important in a geological 
point of view ; for the denominations of Andes and Cor- 
