704 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



tip shorter than tarsus, but decidedly longer than commissure. Tail 

 equal to ( W. canademis) or longer than ( W. mitrata, W. pusilla) dista.nce 

 from bend of wing to tips of secondaries, slightly rounded or double- 

 rounded, the rectrices rather narrow, with subacuminate tips. Tarsus 

 decidedly less than to nearly one-third as long as wing, its scutella 

 indistinct (obsolete or fused except on lower portion); middle toe, with 

 claw, decidedl}' shorter than tarsus; basal phalanx of middle toe united 

 for most of its length to outer toe, for about half its length to inner toe. 



Coloration. — Under parts yellow (under tail-coverts white in one 

 species), the throat sometimes black or partly black, the chest some- 

 times streaked or spotted with black; upper parts plain olive-green 

 or gray, with or without black on crown. 



Nidification. — Terrestrial or subterrestrial (in forest undergrowth). 



^an^e.— Whole of North America (except treeless arctic district); 

 south in winter to northern South America, Cuba, and Jamaica; one 

 species,' referred to this genus, peculiar to Colombia and Ecuador. 

 (Three, or possibly five, species.) 



KEY TO THE SPECIES AND SUBSPECIES OF WILSONIA. 



a. Lateral rectrices with inner webs partly white. 

 6. No whitish or yellowish markings on wings. ( Wilsonia milrata. ) 

 c. Forehead, sides of head, and under parts of body rich yellow; crown, occiput, 

 throat, and chest black. (Eastern United States; south in winter to Cuba, 

 Jamaica, and through eastern Mexico and Central America to Isthmus of 



Panama. ) Wilsouia mitrata, adult male (p. 705) 



cc. Forehead, sides of head, and under parts duller yellow, the first sometimes 

 olive-green; no black on head, throat, or chest, or else the black areas of 

 the adult male imperfectly represented. 



Wilsonia mitrata, adult female (p. 706) 

 bb. Two white or yellowish bands across wing. (Eastern United States.) 



Wilsonia microcepliala, adult male ? (p. 709) 

 aa. Lateral rectrices without white on inner webs. 

 b. Upper parts olive-green; under tail-coverts yellow, like rest of under parts; 

 smaller (wing not more than 60, usually much less). ( Wilsonia pusillu.) 

 c. Forehead and superciliary region bright yellow; crown glossy black. (Adult 

 males and some adult females. ) 

 d. Duller olive-green above, duller yellow below. (Eastern North America; 

 south in winter through eastern Mexico to Guatemala. ) 



Wilsonia pusilla pusilla (p. 710) 

 dd. Brighter olive-green above, brighter yellow below. (Western North 

 America. ) 

 e. Larger (adult male averaging, wing 57.5, tail 50.1; adult female, wing 55.4, 

 tail 48.3); coloration less intense, with upper parts less yellowish, the 

 forehead and superciliary region rich yellow but not inclining to orange. 

 (Western North America in general, breeding from mountains of west- 

 ern Texas to Alaska, but not on Pacific coast south of British Columbia.) 



Wilsonia pusilla pileolata (p. 71-) 



^ Mijiodioctes meridianalis Pelzeln, Verz. zool.-bot. Gossclsch. Wicn, 1882, 416.— 

 Sharpe, Cat. Birds Brit. Mus., x, 1885, 437. 



This species, which may not belong to this genus, is said to resemble W. pusilht, 

 but to differ in being "larger, and having the forehead black, not yellow." 



