258 AVES: RAPTORES. — XL 
brown. L.12. W.7. T. 6. N. Am.; abundant; a small but 
courageous hawk. The species of this genus are more destructive 
among poultry than any other hawks. (Lat., swift.) 
808. A. cooperi Bonaparte. Caicken Hawk. Tail rounded; 
tarsus never booted; colors similar, more blue, the top of head 
darker, the tail more plainly white tipped. L.18. W.10. T. 8. 
N. Am., common. (To Wm. Cooper, of New York.) 
aa, Tarsus feathered about half way down in front, the feathers scarcely sep- 
arated behind. (Astus Lacépede.) 
809. A. atricapillus (Wilson). GosHawx. Chiefly slate blue 
with white superciliary stripe; lower parts white, finely barred 
with brown; tail with four dark bars. L. 24. W. 14. 1.11. 
Northern, S. to U. 8. in winter. (Lat., black-haired.) 
421. BUTEO Cuvier. (Lat. buzzard, as these hawks are called 
in England.) 
a. Outer web of primaries without white, buffy, or ochraceous spots. 
6. Four outer primaries emarginate on inner web. 
c, Head and neck uniform dark sooty brown, or streaked with white, 
never with buffy or reddish. 
810. B. harlani (Audubon). Buack Hawk. Tail irregularly 
mottled with grayish, rusty, white, or blackish and with a dark 
band near tip; general color usually very dark but variable. L. 
21. W.16. T.10. S. W., E. to Ill, searce (subsp. of no. 811). 
cc. Head and neck more or less streaked with ochraceous or rusty red. 
811. B. borealis (Gmelin). Hen Hawk. Rep-TarLep Buz- 
ZARD. Dark brown; much barred and streaked; tail in adult 
bright chestnut red above, with a narrow black bar near its tip. 
L. 23. W. 153. T. 84. N. Am. common, replaced W. by var. 
cealurus Cassin, dark brown, sometimes uniform. 
6b. Three outer primaries emarginate on inner web. (Tachytriorchis Kaup.) 
d. Wing more than 138. 
812. B. swainsoni Bonaparte. Swarnson’s Buzzarp. Gray, 
variously streaked, usually a bright chestnut or brownish area on 
breast; wings dusky; tail with nine or ten narrow dark bars; 
variable. L. 20. W.16. T.8}. W.U.S., E.to Ind. and Mass. 
(To Wm. Swainson.) 
dd. Wing less than 12. 
813. B. latissimus (Wilson). Broap-WinGED Hawk. Brown 
above, whitish or fulvous below, variously streaked and barred ; 
conspicuous dark cheek patches ; tail with broad dark bands alter- 
nating with narrower pale ones, white-tipped; lower parts brownish 
with whitish spots ; in young whitish with darker streaks. L. 18. 
