ftidgway.] 86 [May 21, 



ondaries and primaries with more or less of rufous. Beneath whit- 

 ish, usually tinged more or less with ochraceous, the anterior parts 

 plain brownish (in adult), or longitudinally striped (in young), the 

 posterior portion (from the breast back) transversely barred. Wing, 

 8.70-10.80; tail, 6.50-8.00; culinen, .70-.80 ; tarsus, 2.25-2.40; 

 middle toe, 1.20-1.40. Hab. Whole of Tropical America. 



2. R. leucorrhous. Entirely brownish black, the tail coverts 

 (upper and lower) and lining of the wing white, the latter with an 

 ochraceous tinge; inner webs of primaries barred, or mottled trans- 

 versely, with white. Tail faintly tipped with grayish, and crossed by 

 2-3 faintly indicated bars of grayish brown, passing into white on 

 the inner webs. Inner side of tibia? chestnut-rufous. Wing, 7.80- 

 9.20; tail, 6.00-6.50; culmen, .65; tarsus, 2.25-2.35; middle toe, 

 1.25-1.30. Hab. Northern half of South America. 



1. Buteo (Rupornis) magnirostris (Gmelin). 



Sp. ch. Wing, 8.70-10.80; tail, 6.50-8.00; culmen, .70-.80; tar- 

 sus, 2.25-2.40; middle toe, 1.20-1.40. 



Fourth and fifth, or fifth, quills longest. Tail rounded. Young 

 and adult stages scarcely different. Above, plain grayish, vary- 

 ing from pure ashy to umber, — the head most ashy ; secondaries 

 and primaries with more or less of bright rufous on their inner 

 webs, this also conspicuous on the outer webs of the inner prima- 

 ries, and usually narrowly and distantly barred with dusky. Up- 

 per tail coverts white, barred with brown. Tail varying from 

 pure cinereous to deep rufous, and crossed by from three to seven 

 bands of dusky. Beneath white from the breast hack, barred trans- 

 versely with brown, usually of a reddish cast. Adult. Anterior 

 lower parts plain brownish (always?). Young. Anterior lower 

 parts striped with dark brown upon a whitish ground. (Tail bands 

 more numerous?) 



SYNOPSIS OF THE GEOGRAPHICAL RACES. 



A. — Tail grayish brown, or ashy, without any tinge of rufous. 



1. Tail pure light ash, concolor with the back, the 3-4 

 broad black zones about equal in width to the gray ones; 

 jugulum plain ash; lower parts pure white, broadly barred 

 with reddish ashy. Wing, 8.50-9.50; tail, 6.50-7.00; 

 tarsus, 2.25-2.40; middle toe, 1.20-1.30. Hab. Northern 

 South America . var. magnirostris. 





