AMERICAN WARBLERS. 431 



Conn, and Mass.; north in March, south in 

 Aug. and Sept. Occurs in open woodlands, 

 usually in tree tops. Song, a short, low 

 warble. 



491. SYCAMORE WARBLER. 



Smaller than last, line over eye with 

 little or no yellow. Mississippi Valley, 

 north to southern Mich., east to Ohio and 

 casually to S. C. in migration. 



492. BLACK-THROATED BLUE 

 WARBLER. 



Size of last, blue above, white beneath, 

 spot on wing and spots on tail white, fig. 

 341. Female, green-brown above, lighter 

 below; white wing spot present. Breeds 

 from mountains of Penn. east to western 

 Mass, through Worcester Co.; north to 

 Hudson Bay; winters in Bahamas, West 

 Indies and north eastern S. A.; south in 

 Sept., north in May. Song, a short rather 



