348 Observations on the 
live both on the plains and mountains, and even by the abjection of 
their manners, render an important service to certain towns, by re- 
moving the impurities allowed to accumulate by the negligence of 
the inhabitants. The remainder of the series of vultures of Lin- 
naeus belong to the old world. 
We conceive, that we ought to separate from the series of the Acci- 
pitres, forming the genus Falco of Linnaeus, with a view to form 
them into a sub-family of thf Falconidse, certain species belonging 
exclusively to America, viz. the Caracara * of Azara and Cuvier, and 
the Rancancat of Vieillot, characterized by the disgusting manners 
of the vultures. They live for the most part on dead and putrid 
animals, or excrements, which leads them, like the cathartes, to ap- 
proach inhabited places, and to migrate along with the wandering 
and savage hordes of the American plains. These birds have been 
distributed through different genera by that judicious observer, Don 
Felix de Azara, without regard to the similarity of their manners. 
Then comes an extensive series of birds spread over the two he- 
mispheres, the Eagles or ignoble birds of prey of Cuvier ; of these 
the " Rostrames'^ of Lesson first present themselves, which are 
found only in America, in inundated places, where they go in large 
troops, employing their singular beak, and disproportionately long 
claws, to lay hold of fishes. Among the " Pygargues," America has 
likewise its peculiar species. The aguia of Azara (Falco aguia, 
Temm.)is everywhere spread over the cold and temperate regions, fre- 
quenting the shores of the sea and the banks of rivers, where it re- 
places our osprey and sea eagle. The Circaeti, birds nearly allied 
to our own Circaetus gallicus, VieilL, are also found in both conti- 
nents ; and the only species of large size occurring in South Ameri- 
ca (Circaetus coronatus, Temm.) is also the only one which braves 
the pestilential gales of the southern regions which it frequents. 
The sanguinary harpy (Harpyia destructor, Sw.) which is con- 
fined to the numerous warm and humid forests of the American 
Torrid Zone, is perhaps the most powerful predatory bird occurring 
in these regions, and is most destructive to the peaceable monkeys, 
which are sometimes the sole inhabitants of these silent forests. The 
eagle-hawks (Spizaetus,) inhabit both continents. Those of Ame- 
rica frequent countries intersected with woods, and also plains and 
marshes ; even the urubitinga || may properly be considered as a 
marsh bird. The gos-hawks and sparrow-hawks (Astur and Acci- 
piter) likewise appertain to both continents. In America, their prin- 
cipal resort is woods and wooded mountains; and they are most 
* Polyborus, Vieill. f Ibycter, Vieill. f Cymindis. Haliaeetus. 
|| Falco urubitinga, Linn. Lath. 
