JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 151 



SECTION 2. Second primary, longest; first and second primaries, 

 emarginate, or notched. 



Back, entirely brown; belly, white, without streaks; under tail 

 coverts, pure white; tarsus, nearly bare. 



Pandion haliaetus carolinensis . 

 American Osprey. Fish Hawk. 

 See No. 172. 



Back, slaty brown and white; under tail coverts, spotted or 

 marked with dusky. Falco rusticolus, 



Gray Gyrfalcon. 

 See No. 167. 



SECTION 3. Third primary, longest. 



Four outer primaries, notched; basal portion of inner webs of 

 primaries, largely white, without bars; thighs, tawny or buff, more 

 or less barred; tarsus, thickly feathered. 



Archibuteo lagopus sancti-johannis. 

 American Rough-legged Hawk. 

 See No. 164. 



Four outer primaries, notched; basal portion of inner webs of 

 primaries, largely white, without bars; thighs, tinged with deep 

 rufous, heavily barred; tarsus, thickly feathered. 



Archibuteo ferrugineus. 

 Ferruginous Rough-legged Hawk. 

 See No. 163. 



General plumage, entirely sooty brown, or black; four outer 



primaries, notched; primaries and tail, with more or less white, or 



gray; tarsus, thickly feathered. Archibuteo lagopus sancti-johannis. 



American Rough-legged Hawk (black plumage). 



See No. 164. 



Three outer primaries, notched; belly and thighs, not white. 



Buteo swainsoni. 

 Swainson's Hawk. 



See No. 160. 



Three outer primaries, notched; a part of inner web of outer 

 primaries, white, showing numerous imperfect bars ; belly and thighs, 

 pure white; back, dark brown. Pandion haliaetus carolinensis. 



American Osprey. Fish Hawk. 

 See No. 172. 



