CHAEACTERISTICS OF NORTH-AMERICAN BIRDS. 



ORDER I. — RAPTORES. Robbers. 



The peculiarities already given of the order Raptores are 

 sufficient to define it among the others mentioned, although 

 many additional features might be named. The order em- 

 braces three families, which are characterized by Keyserling 

 and Blasius as follows : — 



A. — Diurnal Birds of Prey. 



Eyes lateral, with lashes, surrounded by a naked or woolly orbi- 

 tal circle ; the feathers above, .below, and behind the eyes directed 

 backwards, as on the rest of the head ; anterior to the eye, the lore 

 imperfectly clothed with a radiating star of bristles, or with scale- 

 like feathers. The inner toe without the nail, shorter, or as long 

 as the outer. Nostrils opening in the cere. 



Vulturid^. — Bill contracted or indented on the anterior 

 border of the cere, so that the culmen is bow-shaped, or ascending 

 anterior to it. Eyes lying on a level with the sides of the head. 

 Head sparsely covered with downy feathers only, or partially 

 naked. Claws weak, rather slender, and only moderately curved ; 

 the tarsi and bases of the toes reticulated. 



Falconid^. — The bill not contracted, nor the culmen ascend- 

 ing anterior to the cere. Eyes sunken. The head completely 

 covered with compact, perfect feathers. Claws strong. 



B. — Nocturnal Birds of Prey. 



Strigid^. — Eyes directed forwards ; more or less completely 

 surrounded by a crown of radiating bristly feathers. Lores and 

 base of bill densely covered with bristly feathers directed forwards. 

 The nostrils opening on the anterior edge of the cere. The inner 

 toe without its claw longer than the outer, which is versatile. A 

 crown of peculiarly formed feathers on the side of the head and 

 above the throat. Head fully feathered. Plumage very soft 

 and downy. 



