660 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



e. Hinder crown and occiput olive-green; back, etc., bright yellowish olive- 

 green; beneath bright lemon yellow, the sides and flanks olive-green; ' 

 tail less than 50; bill stouter, the exposed culmen 13-14. (Southern 

 Honduras to Costa Rica.) 



Geotlilypis semiflava bairdi, adult male (p. 682) 

 e«. Whole pileum black; back, etc., brownish olive-green; beneath saffron 

 yellow, the sides and flanks brownish; tail more than 55; bill more 

 slender, the exposed culmen 12-12.7. (Southeastern Mexico.) 



Geothlypis speoiosa, adult male (p. 683) 

 bb. Tail much longer than wing, 

 c. Post-facial region more or less gray; bill larger (exposed culmen 11-11.5). 

 (States of Vera Cruz and Puebla, southeastern Mexico. ) 



Geothlypis nelsoni nelsoni, adult male (p. 685) 

 cc. Post-facial region olive-green, like rest of upper parta, or but slightly tinged 

 with gray; bill smaller (exposed culmen 10). (State of Hidalgo, south- 

 eastern Mexico. ) Geothlypis nelsoni miororhyncha, adult male (p. 685) 



an.. No black on head. (Adult females and young. ) 



6. Tail not longer than wing (usually decidedly shorter), 

 c. Back, etc., clear olive-green, yellowish olive-green, or grayish olive-green; 

 sides and flanks not. reddish brown; yellow of under parta not of a fulvoas 

 or ochraceous hue. 

 d. Sides and flanks not olive-green. 

 e. Forehead and superciliary region not yellow; if tinged with yellow the 

 color not strongly nor abruptly contrasted with the olive, olive- 

 greenish, or brownish of crown and occiput; under parts not saffron 

 yellow. 

 /. Smaller (wing less than 57 or else exposed culmen less than 12.9— 

 usually less than 55 and 12, respectively). 

 g. Under part partly buffy whitish; smaller (wing and tail less than 55). 

 h. Smaller (wing averaging less than 50, exposed culmen averaging 

 not more than 10). 

 i. Paler; wing averaging 49.7, tail 46.9, exposed culmen 9.7, tarsus 



19.7 Geothlypis trichas trichas, adult female (p. 662) 



a. Darker; wing 48, tail 43, exposed culmen 10, tarsus 19. 



Geothlypis trichas sinuosa, adult female (p. 67?) 

 hh. Larger (wing averaging more than 51, exposed culmen more 

 than 10). 

 i. Darker olive above and on flanks; tail relatively longer and bill 

 larger; wing averaging 52.3, tail 50.5, exposed culmen 11. 



Geothlypis trichas ignota, adult female (p. 667) 

 ii. Paler olive or olive-greenish above and on flanks; tail relatively 

 shorter and bill smaller. 

 j. More decidedly olive-greenish above. 



k. Smaller (averaging wing 51.7, tail 46.8, exposed culmen 10.7, 

 tarsus 19.9). 



Geothlypis trichas brachidactyla, adult female (p. 664) 

 kk. Larger (averaging wing 53.4, tail 50.8, exposed culmen 10.9, 

 tarsus 20.3). 



Oeothl3rpis trichas occidentalis, adult female (p. 669) 

 i;. Duller, more grayish, olive-green above. 



k. Wing averaging 51.9, tail 48.9, exposed culmen 10, tarsus 



20.1 Geothlypis trichas arizela, adult female (p. 670) 



kk. Wing averaging 52, tail 48.2, exposed culmen 10.3, tarsus 

 19.5 Geothlypis trichas modesta, adult female (p. 672) 



