460 SINUOSITIES OF THE RIVEK. 





toda specie. Between the confluence of the Padamo and 

 that of the Mavaca, the Orinoco receives on the north the 

 Ocamo, into which the Bio Matacona falls. At the sources 

 of the latter live the Gruainares, who are much less copper- 

 coloured, or tawny, than the other inhabitants of those 

 countries. This is one of the tribes called by the mis- 

 sionaries 'fair Indians' (Indios blancos). Near the mouth 

 of the Ocamo, travellers are shown a rock, which is the 

 wonder of the country. It is a granite passing into gneiss, 

 and remarkable for the peculiar distribution of the black 

 mica, which forms little ramified veins. The Spaniards call 

 this rock Piedra Mapaya (the map-stone). The little frag 

 ment which I procured indicated a stratified rock, rich in 

 white feldspar, and containing, together with spangles of 

 mica, grouped in streaks, and variously twisted, some 

 crystals of hornblende. It is not a syenite, but probably a 

 granite of new formation, analagous to those to which the 

 stanniferous granites (hyalomictes) and the pegmatites, or 

 graphic granites, belong. 



Beyond the confluence of the Macava, the Orinoco sud- 

 denly diminishes in breadth and depth, becoming extremely 

 sinuous, like an Alpine torrent. Its banks are surrounde'd 

 by mountains, and the number of its tributary streams 

 on the south augments considerably, yet the Cordillera on 

 the north remains the most elevated. It requires two days 

 to go from the mouth of the Macava, to the Rio Glehette, 

 the navigation being very difficult, and the boats, on account 

 of the want of water, being often dragged along the 

 shore. The tributary streams along this distance are, on 

 the south, the Daracapo and the Amaguaca ; which skirt on 

 the west and east the mountains of Gruanaya and Yumari- 

 quin, where the bertholletias are gathered. The Eio Mana- 

 viche flows down from the mountains on the north, the 

 elevation of which diminishes progressively from the Cerro 

 Maraguaca. As we advance further up the Orinoco, the 

 whirlpools and little rapids (chorros y remolinos) become 

 more and more frequent; on the north lies the Cano 

 Chiquire, inhabited by the Gruaicas, another tribe of white 

 Indians; and two leagues distant is the mouth of the 

 Grehette, where there is a great cataract. A dyke of gra- 

 nitic rocks crosses the Orinoco , these rocks are, as it were, 



