658 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



h. Smaller (wing averting 52.9, tail 49.3, exposed culmen 10.5); 

 paler, with yellow of under parts usually confined to throat, chest, 

 breast and under tail-coverts, the back, etc. , more grayish. (Mid- 

 dle portion of Atlantic coast district; Bahamas in winter.) 



Geothlypis trichas trichas, adult male (p. 661) 

 hh. Larger (wing averaging 55.1, tail 49.2, exposed culmen 11.4); 

 deeper colored, the yellow of under parts usually covering moat 

 of the under surface, the back, etc., more decided olive-green. 

 (Northern New Jersey, Long Island, New England States and 

 maritime British Provinces westward to eastern North Dakota 

 and Manitoba, and southward through Mississippi Valley, east 

 of the Great Plains; in winter to Bahamas, Cuba, Jamaica, 

 Porto Rico, and Swan Island, and through eastern Mexico and 

 Central America to Costa Rica. ) 



Geothlypis triclias brachidaotyla, adult male (p. 664) 

 gg. Coloration darker, the back, etc., deep olive-green, the crown 

 (except anteriorly) and occiput olive-brown, the flanks deep buffy 

 olive; wing more rounded, the outermost (ninth) primary usually 

 shorter than second; tail relatively longer, nearly (sometimes 

 quite) equal in length to wing. (Southern coast district of eastern 

 United States, from southeastern Virginia to Florida and eastern 



Texas. ) Geothlypis trichas ignota, adult male (p. 667) 



ff. Post-facial band white or grayish white. (Western forms.) 



g. Under parts of body partly buffy whitish, at least the lower abdo- 

 men; smaller (wing and tail averaging less than 60). 

 h. Larger (wing averaging more than 55, tail more than 50) ; color of 

 upper parts and flanks paler. 

 i. Larger (wing averaging 57.5, tail 55.8); coloration brighter, with 

 yellow of under parts usually more orange. ( Western United 

 States, from western portion of Great Plains to southern Cali- 

 fornia, northern Lower California, and northern Mexico. ) 



Geothlypis trichas occidentalis, adult male (p. 668) 



M. Smaller (wing averaging not more than 55.8, tail 52.6 or less); 



coloration duller, with yellow of under parts usually less 



orange. 



jj. Bill much smaller (exposed culmen rarely 11, averaging 10.3). 



(Pacific coast district, from southern California to British 



Columbia. ) Geothlypis trichas arizela, adult male (p. 670) 



j. Bill much larger (exposed culmen more than 11, averaging 

 11.4). (Western Mexico.) 



Geothlypis trichas modesta, adult male (p. 672) 

 hh. Smaller (wing averaging 52.6, tail 48.3) ; color of upper parts and 

 flanks darker. (Salt marshes of San Francisco Bay.) 



Geothlypis trichas sinnosa, adult male (p. 672) 

 gg. Under parts entirely bright yellow; larger (wing averaging 61.2, 

 tail 60.2). (Southeastern and central Mexico.) 



Geothlypis trichas melanops, adult male (p. 673) 



ee. Larger (wing exceeding 60, exposed culmen not less than 14). (Bahama 



forms: Oeolhlypis roslrata and allies.) 



/. Post-facial band pale gray or grayish white; back, etc., duller, more 



grayish, olive-green; crown more extensively gray; yellow of under 



parts paler and duller. 



g. Larger (wing averaging 62.4, tail 58.2, tarsus 22.8); crown more 



extensively and clearlygray. (New Providence Island, Bahamas.) 



Geothlypis rostrata, adult male (p. 674) 



