164 BIRDS OF ILLINOIS. 



wings, more even tail, and larger toes and claws. It is also very 

 similar to Seiurus, differing chiefly in the longer wings, larger claws, 

 and absence of spots beneath." (Hist. N. Am. B.) 



COMMON CHAEACTEBS. Above plain olive-green, beneath plain yellow (except on throat 

 and jugulum, in 0. agilis alone). 



1. 0. agilis. Adult male: Head, neck and jugulum ash-gray, lighter on the throat and 

 tinged with olive on the crown; a distinct white orbital ring. Adult female: Throat 

 and jugulum light smoky gray, upper head and nape olive, like the back, and yellow 

 of lower parts paler and duller. Young in first autumn: Similar to the female, but 

 throat and jugulum still duller and more or less tinged with dull yellowish. 



2. 0. formosa. A dull male: Crown black, the feathers tipped with ash-gray: lores and 

 triangular patch on auriculars black; broad superciliary stripe, spot on lower eyelid, 

 and entire lower parts rich yellow. Adult female: Similar to the male, but rather 

 duller. Young: Like the adult female, but still duller, the black patches concealed 

 or replaced by dusky smoky olive. 



Geothlypis agilis (Wils.) 



CONNECTICUT WAEBLEE. 

 Popular synonym. Gray-headed Warbler. 



Sylvia agilis WILS. Am. Orn. v, 1812, 64. pi. 39, flg. 4. AUD. Orn. Biog. ii, 1834, 227. pi. 138. 

 Trichas agilis NUTT. Man. 2d ed. i, 1840, 463. 



Sylvicola agilis JAED. AUD. Synop. 1839, 63; B. Am. ii, 1841, 71. pi. 99. 

 Oporomis agilis BAIBD, B. N. Am. 1S68, 246; ed. 1860, pi. 79, flg. 2; Cat N. Am. B, 1859, 

 No. 174; Review, 1866, 218. COUES, Key. 1872.106; Check List, 1873. No. 95; 2d ed. 1882. 

 No. 139; B. Col. Val. 1878, 308.-B. B. & E. Hist. N. Am. B. i. 1874, 290. pL 16. figs. 1. 2.- 

 BIDOW. Nom. N. Am. B. 1881, No. 118. 

 Trichas tephrocotis NUTT. Man. 2d ed. i, 1840, 462. 



HAB. Eastern United States and British Provinces, migrating northward in spring 

 chiefly through the Mississippi Valley, and returning southward in autumn through the 

 Atlantic States. Winter residence unknown, but probably in Gulf States, there being no 

 extralimital record. Breeds in Manitoba, and probably elsewhere in the interior of 

 British America. 



"Sp. CHAB. Springmale. Upper parts and sides of the body uniform olive-green, very 

 slightly tinged with ash on the crown. Sides of the head ash, tinged with dusky beneath 

 the eye. (Entire head sometimes ash.) Chin and throat grayish ash, gradually becoming 

 darker to the upper part of the breast, where it becomes tinged with dark ash. Sides of 

 the neck, breast, and body, olive, like the back; rest of under parts light yellow. A broad 

 continuous white ring round the eye. Wings and tail feathers olive (especially the latter), 

 without any trace of bars or spots. Bill brown above. Feet yellow, length, 6 inches; 

 wing, 3.00; tail, 2.25. Female. The olive green reaching to the bill, and covering sides 

 of head; throat and jugulum pale ashy buff. Young not seen. Nestling unknown. 



"Autumnal specimens nearly uniform olive above; the throat 

 tinged with brownish so as to obscure the ash. 



"A specimen in the collection of the Philadelphia Academy, killed 

 by Mr. Krider, has the darker ash of the jugulum of a decided 

 sooty tinge. 



"A peculiarity in the history of this species is shown in the fact 

 that it is quite abundant in Illinois, Wisconsin, etc., in the spring, 



