298 



NUUTJl AMKIUCAN BIRDS. 



both of which belong to North America, one of them (A. lafjopva) being 

 found also in Euroiie iuul Africa. These differ very considerably from each 

 other, in the details of external structure, probably quite as niucli as they do 



54338,^. 



illu ,ial^S';^ 



54338, ^. 



54338, f 



54338,? ««««4- 



54338, Arcliibuteo fagopus. 



41720, A. ffrruginrn^. 



from the Asiatic forms above mentioned. Tlie following synopsis will ex- 

 press the differences between the two North American species, and lietweeu 

 the American and European races of the one common to both continents. 



Species and Races. 



Common Cn.VRAOTERS. Tail more or less white basally ; inner wobs of the pri- 

 maries white, without bars, anterior to their emargination. Head and neck 

 with longitudinal streaks of whitish and dusky (except in tnelanistic individuals 

 of lagopvs var- sancti-johannis). 



1. A. ferrugineus. Winfr, 15.90-17.00: tail, 9.50-11.00: ciilmen, 1.00- 

 1.20; tarsus, ..!. 10 -3,45; middle toe, 1.40-1.65. Bill wide, the ba,se very 

 broad and depressed. Beneath, continuous pure white, without r-onspicuous 

 spots, except soraetimes a few scattered ones along the sides and across the 

 abdomen ; breast immaculate, or with only narrow shaft-streaks. Upper 

 part-s always with more or less rufous. Adult. Upper parts and tibije 



