522 NORTH AMERICAN BIRDS. 



without black patch. Adult female and immature birds 

 similar to corresponding stages of G. Philadelphia, but eye- 

 lids with a distinct whitish mark. Length 5.00-5.75, 

 wing (male) 2.30-2.50 (2.38), tail 2.10-2.55 (2.28), tarsus 

 .80-.87 (.85); female somewhat smaller (wing 2.25-2.30, 

 tail 2.10-2.30). Nest near ground, in clumps of weeds, 

 often in open places, in mountains. Eggs .71 X -53, white, 

 or buffy white, speckled on larger end with dark brown 

 and lilac-gray, often mixed with a few fine black "pen- 

 lines," and sometimes touched with rusty stains. (Much 

 like eggs of G. trichas.} Hab. "Western North America 

 (chiefly in mountains) north to British Columbia ; in win- 

 ter, south through whole of Mexico and Central America to 

 Panama. 



680. G. macgillivrayi (AuD.). Macgillivray's Warbler. 



b 1 . Tail not decidedly shorter than wing (often longer), with less than basal 

 half concealed by the coverts ; first quill shorter than fifth (often shorter 

 than sixth) ; outstretched feet falling far short of tip of tail. (Subgenus 

 Geothlypis.) 



c l . Bill only moderately slender and acute (sometimes decidedly stout) ; 

 black mask of adult male not extending over crown, and always 

 bordered posteriorly by ashy, whitish, or yellow; legs and feet 

 light brown or pale horn-color. 



d*. Exposed culmen less than .52 ; bill slender, scarcely, if at all, deeper 

 than broad at base, the culmen nearly straight or only slightly 

 curved. 



e l . Tarsus not more than .85 ; exposed culmen less than .48 ; adult 

 male with black mask bordered behind by ashy or white. 

 (Adult females without any black, ashy, or white about head, 

 the whole top and sides of head being grayish brown or 

 olive, often tinged with reddish brown on crown ; yellow 

 of lower parts paler and usually more restricted than in 

 male, nearly the whole lower surface sometimes dull yel- 

 lowish white. Adult male in winter same as in summer, but 

 more or less washed with brown above, especially on top 

 of head, the black of mask somewhat obscured by slight 

 brownish or light-colored tips to feathers, and light gra} T - 

 ish or whitish border more or less concealed by brown tips. 

 Young male in first winter similar to adult, but mask much 

 less distinct, often merely indicated. Young : Plain olive 

 above, pale olive-yellowish beneath.) 



/*. Lower parts not entirely yellow, the anal region, at least, 

 buffy whitish, and flanks either dull buffy whitish or 

 brownish, distinctly different from color of belly ; wing 

 less than 2.40. 



