460 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Coloration. — Above plain dusky slate, olive, or olive-green, the 

 pileum rufous or with light-colored median stripe (whole head and neck 

 sometimes rufescent); beneath yellow, or white with chin and throat 

 yellow, white, or gray; never streaked nor spotted, either [above or 

 below, except in nestling plumage. 



Range. — Mexico to Peru, Bolivia, Argentina, and Guiana, in high- 

 lands. 



The type of this genus is somewhat more slender, with smaller bill 

 and narrower rectrices, than the other species which I consider to be 

 congeneric with it (usually referred to the genus Bvurremon), but the 

 structural differences between A. fileatus and any of the others are 

 very insignificant compared with those between different species of 

 Aimophila., Ammodramus, Cardinalis, Pipilo, and other genera. 



KEY TO THE SPECIES AND SUBSPECIES OP ATLAPETES. 



<!. Pileum uniform rufous; rest of upper parts olive-green; sides of head gray 

 (becoming blackish on lores and orbits). {Atlapetes pileatns.) 

 b. Darker and browner above, with under parts brighter yellow. (Southern and 



central portions of Mexican plateau.) Atlapetes pileatns pileatus (p. 460) 



bb. Paler and grayer above, with under parts paler yellow. (Northwestern por- 

 tion of Mexican plateau.) Atlapetes pileatus dilutus (p. 461) 



aa. Pileum black, relieved by a white median stripe; rest of upper parts olive-dusky 

 or dark slaty; sides of head black. 

 b. Under parts yellow medially, olivaceous laterally. (Southern Mexico; Colom- 

 bia.) Atlapetes albinuclia (p. 463) 



bb. Only the chin, throat, and malar region yellow, the rest of under parts white 

 medially, gray laterally. (Guatemala to Colombia. ) 



Atlapetes gnttnralis (p. 461) 



ATLAPETES PILEATUS PILEATUS Wagler. 

 RUTOUS-CAPPED SPARROW. 



Adults {sexes alike), — Entii'e pileum chestnut-rufous; rest of upper 

 parts plain olive-brownish, passing into gray on sides of head and 

 neck; under parts yellow, tinged with olive laterally; maxilla black 

 or blackish brown, mandible horn brownish; legs and feet light 

 brownish. 



Young. — Pileum olive-brownish, like back, etc.; under parts dull 

 buffy yellowish, becoming olive- brownish on sides and flanks, the 

 chest more or less mottled or clouded with light brownish. 



AdAilt TOffl^e.— Length (skins), 127.00-152.40 (liS.SO): wing, 63.50- 

 71.12 (67.06); tail, 64.26-73.15 (71.63); exposed culmen, 10.92-12.45 

 (11.94); depth of bill at base, 6.35-8.13 (7.37); tarsus, 23.37-25.40 

 (24.38); middle toe, 14.48-16.76 (16.00).^ 



Adn.ilt female.— hQngth. (skins), 137.16-152.40 (144.78); wing, 61.72- 

 69.85 (65.02); tail, 62.23-73.66 (67.06); exposed culmen, 11.43-12.70 

 (11.94); depth of bill at base, 7.11-8.13 (7.37); tarsus, 23.37-25.40 

 (24.13); middle toe, 15.24-16.51 (15.75).'' 



' Thirteen specimens. ^ Five specimens. 



