618 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



uals); maxilla dark grayish brown (dull slate color in life), mandible 

 paler (bluish white, sometimes tinged with lilac, in life); iris dark 

 brown; legs and feet bluish gray (in life). 



Admit onale in wvnter. — ^^Not essentially different from the summer 

 plumage, but with rather more light cinnamon or buffy on the upper 

 parts, the feathers of pileum usually more or less edged with the 

 latter color. 



Adult female in summer. — Above dusky grayish brown or olive, 

 streaked, especially on back and along median line of pileum, with pale 

 tawny, buffy, or whitish; wings and tail grayish brown, with white 

 markings much more restricted than in adult males, those on tail 

 nearly if not quite obsolete; superciliary stripe, chin, sides of throat, 

 and malar region whitish; chest, more or less extensively, pale ful- 

 vous, cinnamon-buffy or j'^ellowish buffy; abdomen usually pale yellow, 

 sometimes white; sides and flanks more or less streaked with dusky, 

 the breast also sometimes narrowly streaked. 



Adult feimde in winter. — Similar to the summer plumage, but with 

 the bufl'y or cinnamoneous hues more pronounced and the broad lateral 

 crown-stripes grayish brown or olive streaked with black. 



Young {both sexes?). — Similar to adult female, but superciliary and 

 malar stripes purer white, lateral crown-stripes and auricular patch 

 uniform brownish black, under parts paler and without yellow on 

 abdomen, and back spotted rather than streaked. 



Adiilt maZt'.— Length (skins), 167.6dt-195.58 (181.10); wing, 94.49- 

 109.22 (99.82); tail, 70.8T-85.85 (79.2.5); exposed culmen, 15.24-20.32 

 (17.53); depth of bill at base, 13.21-17.53 (14.99); tarsus, 20.83-25.40 

 (23.62); middle toe, 15.24-19.05 (17.58).' 



Adidt female.— hengt\i{iikms), 156.21-198.12 (180.09); wing, 94.49- 

 104.65 (98.30); tail, 68.58-86.36 (76.45); exposed culmen, 15.49-19.81 

 (18.03); depth of bill at base, 13.97-16.26 (14.73); tarsus, 22.35-25.65 

 (23.62); middle toe, 16.51-18.80 (17.63).' 



Western United States and plateau of Mexico; north, in summer, 

 to British Columbia, Idaho, Montana, etc. , east to southeastern Dakota 

 (accidentally to Michigan), eastern Nebraska and eastern Kansas; 

 breeding south to southern portion of Mexican plateau. 



Ouiraca melanocephala Swainson, Philos. Mag., new. ser., i, 1827, 438 (Temascalte- 

 pec, Mexico). — Bonaparte, Proc. Zool. Soc. Lond., 1837, 111 (Mexico); Geog. 

 and Comp. List, 1838, 30.— Baikd, Rep. Pacific R. R. Surv., ix, 1858, 498; 

 Cat. N. Am. Birds, 1859, no. 381; Proc. Ac. Nat. Sci. Pliila., 1859, 301, 304 



' Sixty-two specimens. 



'^ Twenty-one specimens. 



As in the case of Ouiraca aerulea lazula, there is considerable geographic varia- 

 tion in measurements in this species, California specimens being the smallest; but in 

 this case Mexican examples, instead of being the largest, are nearly as small as those 

 from California, the largest being those from the Rocky Mountain district of the 

 United States. There is a great amount of individual variation in all the measure- 



