460 
SINUOSITIES OF THE BIVES. 
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 ialls. At the sources 
of the latter live the Guainares, 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 blaneos). Near the mouth 
of the Ocamo, travellers are shown a rock, which is th 
wonder of the country. It is a granite passing into gneiss, 
and remarkable for the peculiar distribution of the biacK 
mica, which forms little ramified veins. The bpamards caU 
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 ol 
mica, grouped in streaks, and variously twisted, som 
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 surrounded 
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 Bio Gehette, 
the navigation being very difficult, and the boats, on accouu 
of the want of water, being often dragged along the 
shore. The tributary streams along this distance are, on 
the south, the Daraeapo and the Amaguaca; which skirt on 
the west and east the mountains of Guanaya and lumari- 
quin, where the bertholletias are gathered. The Bio Mama" 
viche flows down from the mountains on the north, t 
elevation of which diminishes progressively from the Gerr 
Maraguaca. As we advance further up the Orinoco, th 
whirlpools and little rapids (chorros y remolmos) become 
more and more frequent; on the north lies the Cano 
Ohiquire, inhabited by the Guaicas, another tribe of whim 
Indians; and two leagues distant is the mouth of th 
Gehette, where there is a great cataract. A dyke of gr^ 
nitic rocks crosses the Orinoco ; these rocks are, as it were, 
