ORDER RAPTORES. 163 



b. Halueetus leucocephalus alasc&nug C. H. Townsend. Northern Bald 

 [352a.] 



Halioetus leiu>ocephalits alascanus Townsbnd, Proc. Biol. Soe. Wash., 

 XI, June 9, 1897, 145. (Unalaska, Alaska.) 



Range.— Boreal zones of northwestern Alaska, northwestern Mackenzie, 

 central Keewatin, and northern Ungava south to British Columbia and the 

 Great Lakes. 



Family FALCONID.a;. Falcons, Caracaras, etc. 



Subfamily FALCONING. Falcons. 



Genus FALCO Linnaeus. 



Falco LiNN^us, Syst. Nat., ed. 10, I, 1758, 88. Type, by subs, desig., 

 Falco subbuteo Linn^us (A. O. U. Comm., 1886). 



Subgenus HIEROFALCO Cuvier. 



Hierofalco Cuvier, R6gne Animal, I, 1817, 312. Type, by monotypy, 

 Falco candicans Gmelin = Falco islandus BrCnnich. 



Falco isldndus Brunnich. White Gyrfalcon. [353.] 



Falco islandus Brunnich, Om. Borealis, 1764, 2. (Iceland.) 



Range. — Arctic regions. Resident in Greenland; in winter 

 casual south to Ontario, Nova Scotia, and Maine. 



Falco rusticolus Linnaeus. 



Range. — Arctic and subarctic parts of the Northern Hemisphere, 

 south in winter to northern part of temperate zone. 



a. Falco rusticolus rusticolus Linn^eus. Gray Gyrfalcon. [354.] 



Falco rusticolus Linn^us, Syst. Nat., ed. 10, 1, 1758, 88. (Sweden.) 



Range. — Arctic regions. Breeds in Arctic America from Alaska east to 

 southern Greenland; in winter casual south to British Columbia, Kansas, 

 Wisconsin, Ontario, and Maine. 



