of the United States. 33 



hook ; lobe strongly marked ; edges of the lower mandible 

 inflexed ; cere not much extended, more or less pilose ; nos- 

 trils oblong, transverse, covered in part by the hair ; lores 

 pilose : head depressed : body slender. Tarsus elongated, 

 slender, scutellated, feathered for a short space : toes rather 

 long, slender ; outer toes connected at base : nails subequal, 

 slender, much incurved, extremely sharp. Wings elonga- 

 ted ; first primary shorter than the fifth ; third and fourth 

 longest. Tail long, nearly even. 



Female and young differing considerably in colour from 

 the male ; often with a kind of collar of small rigid feathers 

 surrounding the face, as in Owls. Plumage changing extra- 

 ordinarily from age. 



Bold : somewhat agile ; flight graceful ; in these respects 

 superior to the Buteones, but inferior to the true Falcons. 

 Do not chase well on the wing. Feed on mice, reptiles, 

 fishes, young birds, and insects. Dwell near marshes and 

 ponds. Build amongst marsh plants. 



21. Falco htemalis, Gm. No collar round the face; wings 

 when closed reaching but little beyond the middle of the tail. 



Adult brown skirted with ferruginous ; head, neck, tail 

 coverts and beneath, white, spotted with brown ; tail barred 

 alternately with dark and light brown. 



Young brown and ferruginous ; beneath rusty, varied 

 with black and white ; wings and tail black, the former spot- 

 ted, the latter crossed by five bands, and tipped with white. 



Winter Falcon, Falco hy emails, Wils. Am. Orn. iv. p. 73. 

 pi. 35. fig. 1. adult male; and Red-shouldered HawJc, Falco 

 lineatus, Id. vi. p. ac. pi. 53. fig. 3. young male. 



Inhabits North America : rather common in Pennsyl- 

 vania during winter. 



22. Falco ctaneus, L. A collar round the face ; wings 



