222 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



qq. Size larger; wings, cf 398-400 mm., 9 

 373-432 mm. (Florida, Bahamas). 

 B. jamaicensis umbrinus, ad.(p. 260) 

 pp. Rectrices usually with only the sub- 

 terminal band; if others present, few in 

 number and small and narrow (eastern 

 and east-central North America). 

 B. jamaicensis borealis, ad. (p. 237) 

 00. Thighs usually distinctlj' rufescent (moun- 

 tains s, Mexico to Panama). 

 B. jamaicensis costaricensis, ad, (p. 265) 

 nn. Thighs usually barred. 



o. Lower breast and abdomen usually with some 



prominent blackish or brownish black 



streaks, sharply demarcated from ground 



color of underparts (western North 



America) . 



B. jamaicensis calurus, light phase, ad. (p. 246) 



00. Lower breast and abdomen either without 



any dark, blackish streaks or with narrow, 



relatively inconspicuous ones. 



p. Breast and upper abdomen indistinctly 



spotted with black (Tres Marias Islands). 



B. jamaicensis fumosus, ad. (p. 264) 



pp. Breast and upper abdomen with no black 



spots. 



q. Breast and upper abdomen with no spots 



at all (Socorro Island). 

 B. jamaicensis socorroensis, ad. (p. 264) 

 qq. Breast and upper abdomen with some 

 tawny streaks (Oklahoma to Texas 

 and north-central Mexico). 

 B. jamaicensis fuertesi, ad. (p. 255) 

 ii. Tail regularly banded (that is, with more than the sub- 

 terminal band), usually grayish, sometimes reddish or 

 whitish, 

 j. Tail decidedly rufescent, not grayish or whitish (moun- 

 tains southern Mexico to Panama). 



B. jamaicensis costaricensis, juv. (p. 265)" 

 jj. Tail grayish, grayish brown, or whitish, not rufescent 

 (sometimes washed with rufous). 

 k. Tail whitish or very pale tawny cream (western 

 Canada to Mexico and Louisiana). 



Buteo jamaicensis kriderii, juv. (p. 257) 



" The immature plumages of B. j. fumosus and B. j. socorroensis are not known; 



