466 Mr. R. Ridgway on the Oenus Empidouax. 



Male : Wiug 2-50-2-90 (2-G5) inches, 

 tail 2-35-2-00 (2-43), ciilmen Oo7-0-63 

 (0-61), width of bill at base 0-25-0-28 

 (0-27), tarsus 0-04-69 (0-G8). Female -. 

 Wing 2-30-2-60 (2-44), tail 2-20-2-45 

 (2-32). — i/rtZ>. Western North America, 

 north to Sitka, south, in winter, to 



Western Mexico -C. difficilis. 



/*. Under wing-coverts yellowish white or 

 pale sulphur-yellow. 

 g^. Wing-bands not darker (usually paler) 

 than lower parts. 

 Above dull olive-green, the wing-bands 

 pale olive-yellowish in adult, buffy 

 in young; lower pai-ts pale dull 

 sulphur-yellow, shaded with ohve 

 across breast. Male : Wing 2 -55-2 -75 

 (2-64) inches, tail 2-10-2-30 (2-18), 

 culmen 0-48-0-59 (0-54), width of 

 bill at base 0-25-0-28 (0-26), tarsus 

 0-64-0-68 (0-66). Female : Wing 

 2-40-2 -50 (2-45), tail 2-00-2-25 ' 

 {2-11).— ITab. Eastern North Ame- 

 rica, south, in winter, through 

 Eastern Mexico and Central Ame- 

 rica to Panama E.Jlaviventris. 



y^. Wing-bands darker than lower parts. 

 7i'. Above dull olive, the wing-bands 

 dull hght olive, sometimes inclining 

 to russet: lower parts pale olive- 

 yellowish, more decidedly olivaceous 

 on breast ; edge of wing dull ochra- 

 ceous or fulvous. Wing 2-60-2-80 

 (2-72) inches, tail 2-40-2-55 (2-49), 

 culmen 0-58-0-60 (0-59), width of 

 biU at base 0-25, tarsus 0-65-0-70 

 (0-68). — Hab. Southern and Eastern 

 Mexico (Oaxaca, Cordova, Mirador, 



&c.) E, bairdii, 



h\ Above bright olive or olive-green. 

 i^. Above bright olive-green, the 

 wing-bands similar but paler, 

 sometimes inclining to ochra- 

 ceous; lower parts greenish sul- 

 phur-yellow, distinctly shaded 



