BITER PORPOISES. 
L !2 
Tlie heat augments sensibly, in the Llanos during the 
rainy season, particularly in the month of July, when the 
sky is cloudy, and reflects the radiant heat toward the earth. 
During this season the breeze entirely ceases ; and, accord- 
ing to good thermometrical observations made by M. Pozo, 
the thermometer rises in the shade to 39° and 39’5°, though 
kept at the distance of more than fifteen feet from the 
ground. As we approached the banks of the Portuguesa, 
the Apure, and the Apurito, the air became cooler from the 
evaporation of so considerable a mass of water. This effect 
is more especially perceptible at sunset. During the day 
the shores of the rivers, covered with white sand, reflect 
the heat in an insupportable degree, even more than the 
yellowish brown clayey grounds of Calabozo and Tisnao. 
On the 28th of March I was on the shore at sunrise to 
measure the breadth of the Apure, which is two hundred 
and six toises. The thunder rolled in all directions around. 
It was the first storm and the first rain of the season. The 
river was swelled by the easterly wind ; but it soon became 
calm, and then some great cetacea, much resembling the 
porpoises of our seas, began to play in long files on the 
surface of the water. The slow and indolent crocodiles 
seem to dread the neighbourhood of these animals, so noisy 
and impetuous in their evolutions, for we saw them dive 
whenever they approached. It is a very extraordinary phe- 
nomenon to find, cetacea at such a distance from the coast. 
The Spaniards of the Missions designate them, as they do 
the porpoises of the ocean, by the name of toninas. The 
Tamanacs call them orimicna. They are three or four feet 
.ong; and bending their back, and pressing with their tail 
on the inferior strata of the water, they expose to view a 
part of the back and of the dorsal fin. I did not succeed 
in obtaining any, though I often engaged Indians to 
shoot at them with their arrows. Lather Gili asserts 
that the Gumanos eat their flesh. Are these cetacea 
peculiar to the great _ rivers of South America, like tbe 
manati, which, according to Cuvier, is also a fresh water 
cetaceous animal ? or must we admit that they go up from 
the sea against the current, as the beluga sometimes does iu 
the rivers of Asia ? What would lead me to doubt this last 
supposition is, that we saw toninas above the great cataracts 
