172 
CXOTJDS 01? MOSQUITOS. 
ance of little flies, or of the genus Simulium, but xancudos, 
which are really gnats, though very different fiom our Euro- 
pean species.* These insects appear only after sunset. Their 
proboscis is so long that, when they fix on the lower surface 
of a hammock, they pierce through it and the thickest gar- 
ments with their sting. 
We had intended to pass the night at the Vuelta del 
Palmito, but the number of jaguars at that part of the 
Apure is so great, that our Indians found two hidden 
behind the trunk of a locust-tree, at the moment when they 
were going to sling our hammocks. We were advised to 
re-embark, and take our station in the island of Apurito, 
near its junction with the Orinoco. That portion of the 
island belongs to the province of Caracas, while the right 
banks of the Apure and. the Orinoco form a part, the one ol 
the province of Varinas, the other of Spanish Guiana. We 
found no trees to which we could suspend our hammocks,, 
and were obliged to sleep on ox-hides spread on the ground- 
The boats were too narrow and too full of xancudos to permit 
us to pass the night in them. 
In the place where we had landed our instruments, the 
banks being steep, we saw new proofs of the indolence of 
the gallinaceous birds of the tropics. The curassaos and 
cashew-birdst have the habit of going down several times 
a-day to the river to allay their thirst. They drink a great 
deal’ and at short intervals. A vast number of these birds 
had joined, near our station, a flock of parraka pheasants- 
They had great difficulty in climbing up the steep banks ; 
they attempted it several times without using their wings- 
We drove them before us, as if we had been driving sheep- 
The zamuro vultures raise themselves from the ground wife 
great reluctance. 
We were singularly struck at the small quantity of watef 
which the Rio Apure furnishes at this season to the Ori- 
noco. The Apure, which, according to my measurement 9 ' 
was still one hundred and thirty-six toises broad at the Can 0 
Rico, was only sixty or eighty at its mouth.* Its depth 
* M. Latreille has discovered that the mosquitos of South Carolina are 
of the genus Simulium (Atractocera meigen.) 
+ The latter (Crax pauxi) is less common than the former. 
Not quite so broad as the Seine at the Pont Royal, opposite t" 
