472 NORTH AMERICAN BIRDS. 



Western United States, east to Eocky Mountains ; south 

 through central and western Mexico in winter. 



— . V. gilvus swainsoni (Baird). 



Western Warbling Vireo/ 



6^ "Wino- with two distinct white bands across tips of middle and greater 



coverts. (Subgenus Lanivireo Baird.) 



&. No spurious primary ; loral streak, oi"bital ring, chin, throat, and breast 



yellow ; top of head olive-green. 



Posterior under parts white ; rump, upper tail-coverts, and scapu- 

 lars ash-gray; hind-neck and back olive-green; tertials broadly 

 edged with white ; length 5.00-5.85, wing 3.00-3.20, tail 2.00- 

 2.30. Nest in woods, usually at a considerable height from 

 ground. Eggs .79 X -58, usually more heavily spotted than in 

 other species. Hah. Eastern United States, west to edge of 

 Great Plains; south, in winter, to Costa Rica. 



628. V. flavifrons Vieill. Yellow-throated Vireo. 

 c^ A more or less distinct spurious primary ; loral streak, orbital ring, 

 chin, throat, etc., white ; top of head ash-gray or jjlumbeous (more 

 brownish in winter). 

 d}. Spurious quill minute (much shorter than exposed culmen) ; hind- 

 part and sides of neck olive-green, like back and scapulars ; 

 chest and breast (especially sides of the latter) strongly washed 

 with sulphur-yellow. (Otherwise much like V. soUtarius.) 

 Wing 3.05, tail 2.20, bill from nostril .30, tarsus .72. Hah. 

 Highlands of Guatemala (Coban, Vera Paz). 



V. propinquus (Baird). Vera Paz Vireo.* 

 d}. Spurious quill well developed (much longer than exposed culmen) ; 

 hind-part and sides of neck grayish, like top of head and ear- 

 coverts ; chest and breast without yellow tinge. 

 e\ Sides and flanks conspicuously olive or olive-green, distinctly 

 tinged with yellow ; back, rump, and upper tail-coverts olive- 

 green. (Young in first winter with anterior upper parts 

 dull grayish brown, the lower parts dull butfy white, the 

 general aspect quite different from full adult plumage.) 

 p. Smaller (wing not more than 3.00, tail rarely more than 

 2.20). 

 g^. Back, etc., brighter olive-green, more abruptly con- 

 trasted with plumbeous-gray of head and neck, 

 the latter deeper and clearer ; gray of cheeks more 

 abruptly contrasted with white of throat; sides 

 and flanks usually more strongly tinged with 



1 Vireo swainsoni Baird, B. N. Am. 1858, 336 (in text). Vireo gilvus, var. swainsoni Coues, Key, 1872, 121. 

 ^ Vireosylvia propinqua Baird, Review Am. B. i. May, 1866, 348. 



This is either a very distinct species or else, as suggested by Messrs. Salvin & Godman {Biol. Centr.-Am., 

 Aves, i. p. 197) a hybrid between V. solitarius and V, flavifrons. 



