280 KEY TO THE BIRDS OF EASTERN NORTH AMERICA. 



Crown, dull olive ; throat, bright yellow; belly, much paler, often whitish; 

 tail, brownish olive, without yellow ; wing, not longer than tail ; males have 

 black patch on face (forehead and sides of head) which is lacking in females. 



Maryland Yellowthroat. 



Geothlypis trichas. 

 See No. 522. 



Throat and belly, nearly the same color; crown, glossy black (male), or olive 

 green like back (female) ; tail feathers, slaty brown 

 faintly washed with olive on outer webs ; numerous 

 small black bristles at base of bill. 



Wilson's Warbler. 

 Wilson's Blackcap. 

 Sylvania pusilla. 

 See No. 526. 



Entire underparts, yellow; brightest on the belly; wing, longer than tail; 

 crown, grayish; back and rump, dull olive; tail feathers, not marked with 



yellow. 



Mourning Warbler. 



Geothlypis Philadelphia (young female) . 

 See No. 521. 



Part 5. The following species have the throat, yellow ; belly, not yel- 

 low ; tail feathers, marked with more or less white : 



Back, black or dark; tail, black, with broad 

 band of white; rump, yellow. 



Black and Yellow Warbler. 



Dendroica maculosa. 

 See No. 500. 



Back, slaty blue, often showing yellowish olive; rump, slate color; sides of 



head, grayish or slaty blue. 



Parula Warbler. 



Blue, Yellowbacked Warbler. 



Compsothlypis americana. ' 



See No. 494. 



Back, dull green; throat, faintly washed with greenish yellow; rump, green; 



sides, not streaked. 



Tennessee Warbler. 



Helminthophila peregrina. 

 See No. 493. 



Back, greenish ; rump, greenish; cheeks, yellowish; sides, showing more or 



less dark streaks. 



Black-throated Green Warbler. 



Dendroica virens. 



