OF BIRDS. 
Vll 
like that of the Mammalia. The six orders of birds, are 
as follows : S 
1. Raptor es, or birds of prey. These birds are distin- 
guished by a very strong and sharp bill more or less curved, 
but always hooked at the extremity of the upper mandible, 
which is covered at the base with a kind of skin called the 
cere. The nostrils are usually open. The legs are very 
strong, and generally only partially covered with feathers ; 
the feet are large, and the toes, which are four in number, 
are armed with very strong, sharp, curved, prehensile claws. 
The principal raptorial birds are the vultures, including the 
condor; the falcon family, including the eagles, hawks, 
kites, and buzzards ; and the owls. 
2. Insessores , or perching birds. These birds have all feet 
formed for perching, the hind toe springing from the same 
place as the other toes, which gives them great power of 
grasping. Their legs are of moderate length, and their 
claws not sharply curved. This order includes the thrushes, 
nightingales, and all the finest songsters of our groves, with 
the robin-redbreast, the sparrow, and other birds seen about 
dwellings, the swallows, the larks, the crow family, the king- 
fishers, the birds of paradise, and the humming birds. 
