154 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



Head, neck and entire under parts, pure white; rest of plumage, 

 glossy bluish black ; wing, less than 1 9 ; primaries, dark slaty, show- 

 ing greenish tinge when held in the light; two outer primaries, notched ; 

 tail, long and forked. Elanoides forficatus. 



Swallow-tailed- Kite. 

 See No. 151. 



Wing, always over 18.50; belly and thighs, never white; only 

 adult birds have the hood and tail white. Haliaetus leucocephalus. 



Bald Eagle. 

 See No. 166. 



SECTION 3. Fourth primary, longest; tarsus, partly (not entirely) 

 feathered. 



Tail, rufous brown (adult); tail, whitish or grayish, with numer- 

 ous brown bars (immature). Buteo borealis, and races. 



Red-tailed Hawk. 

 See Nos. 158, i58a, i^8b, 1580. 



General plumage, dark sooty brown, sometimes with pale under 

 parts, more or less streaked and spotted. Buteo borealis harlani. 



Harlan's Hawk. 



See No. 1580. 



Wing, always over 18.50; only adults have head and tail white. 



Halieeetus leucocephalus. 

 Bald Eagle. 

 See No. 166. 



SECTION 4. Fourth primary, longest; tarsus, entirely feathered. 



Thighs, tawny, more or less streaked or barred. 



Archibuteo lagopus sancti-johannis. 

 American Rough-legged Hawk. 

 See No. 164. 



General plumage, sooty brown or black (black plumage). 



Archibuteo lagopus sancti-johannis. 

 American Rough-legged Hawk. 

 See No. 164. 



