Appendix, 



THE VIREO FAMILY. 



Small, unstreaked birds, without brilliant markings, 

 generally colored in soft tones of* olive-greenish 

 or grayish. Bill slender, but stouter than a 

 warbler's, with which group the vireos may 

 easily be confounded. Active in habits, and 

 with sweet warbling songs. Insect eaters, 

 frequenting trees and groves. Nest a sus- 

 pended cup-shaped basket. All species very 

 similar and difficult to distinguish in life. 

 Length four or five inches. 



154. Warbling Vireo; Vireo gilvus (Vieill.). 



Head brownish gray; back grayish olive, differing 

 but little from head; rump greenish olive; breast 

 dull white; sides pale yellowish; a faint whitish 

 line above the eye; no wing bars. A common, 

 generally distributed summer resident. 



155. Cassin's Vireo; Vireo solitarius cassinii 

 (Xantus). 



Head bluish gray; back grayish olive, contrasting 

 with bluish of head; rump greenish olive; 

 breast dull white; sides pale yellowish; a con- 

 spicuous white ring around eye; two white wing 

 bars. Breeds in the mountains of California, 

 and migrates south through the valleys. 



I 56. Hutton's Vireo ; Vireo huttoni Cass. 



Head dull greenish gray; back greenish olive; 

 rump brighter greenish olive; breast pale oliva- 

 ceous yellowish; sides darker yellowish; a dull 

 whitish ring around eye; two white wing bars; 

 the wings edged with yellowish. A winter 



