NATURAL SCIENCES OF PHILADELPHIA. 79 



Adult. Above slate-color, varying from a fine bluish to a 

 brownish cast, the shafts of the feather black. Pileum plumbeous- 

 black, the occipital feathers snow-white beneath the surface ; pri- 

 maries plain brownish-slate, their shafts clear brown. Tail nar- 

 rowly tipped with white, and crossed by four very regular, but 

 sometimes not sharply defined, bands of dusky, usually rather 

 narrower than the slaty ones the last broadest, the first nearly 

 obsolete, and concealed by the coverts, which are sometimes nar- 

 rowly tipped with white. Lower parts white and rufous, in trans- 

 verse bars, the shafts of the feathers black, and the rufous bars 

 usually connected along the middle portion of the feathers ; tibiae 

 more deeply colored, the rufous usually predominating ; crissum 

 immaculate white. Lining of the wing white, irregularly spotted 

 with deep rufous; inner webs of the primaries with transverse 

 bands of dusky and white anterior to their emargination and sil- 

 very-gray terminally the dusky bands about seven in number on 

 the longest quill, the two colors nearly equal in width. Bill black 

 terminally, pale blue basally ; cere greenish-yellow; iris orange- 

 red ; tarsi and toes lemon-yellow ; claws black. Male : Slate of the 

 upper parts of a fine bluish cast; nape and sides of the head 

 bluish-ashy, the sides of the breast usually tinged with the same. 

 Wing, 8.85-9.40 ; tail, 7.80-8.30 ; culmen, .60-.68 ; tarsus, 2.30-2.60 ; 

 middle toe, 1.45-1.55. (Eight specimens.) Female: Slate of the 

 upper parts of a brownish cast ; nape and sides of the head dull 

 rusty rufous, the sides of the breast without ashy tinge. Wing, 

 10.10-10.80 ; tail, 9.00-9.40 ; culmen, .70-.80 ; tarsus, 2.G5-2.85 ; 

 middle toe, 1.60-1.85. (Five specimens.) 



Young : Above grayish-brown, the feathers more or less bor- 

 dered with rusty; the scapulars and upper tail-coverts with con- 

 cealed white spots; the occiput blackish, with the bases of the 

 feathers white; and the pileum and nape streaked with rusty. 

 Tail grayish-brown, tipped with whitish, and crossed by four 

 bands of brownish-black or dusky. Lower parts white, longitu- 

 dinally striped with clear dusky brown; the shafts black. Iris 

 varying from greenish-white to chrome-yellow ; bill blackish ter- 

 minally, pale blue basally ; tarsi and toes varying from very pale 

 greenish-yellow to lemon-yellow; claws slate-black. 



Remarks. The extent of individual variation in this species, 

 though very considerable, is limited by the terms of the above 

 diagnosis. Adult males vary as follows : 



