466 Mr. R. Ridgway on the Genus Empidonax. 
Male\ Wing 2-50-2-90 (2-65) inches, 
tail 2-35-2-60 (2-43), culmen 0-57-0-63 
(0‘61), width of bill at base 0-25-0-28 
(0 - 27), tarsus 0-64-69 (0*68). Female : 
Wing 2-30-2-60 (2-44), tail 2-20-2-45 
(2-32).— Hab. Western North America, 
north to Sitka, south, in winter, to 
Western Mexico. E. difficilis. 
f 2 . Under wing-coverts yellowish white or 
pale sulphur-yellow. 
g 1 . Wing-bands not darker (usually paler) 
than lower parts. 
Above dull olive-green, the wing-bands 
pale olive-yellowish in adult, huffy 
in young; lower parts pale dull 
sulphur-yellow, shaded with olive 
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).— Hab. Eastern North Ame¬ 
rica, south, in winter, through 
Eastern Mexico and Central Ame¬ 
rica to Panama . E.jlaviventris. 
g 2 . Wing-bands darker than lower parts. 
A 1 . Above dull olive, the wing-bands 
dull light olive, sometimes inclining 
to russet; lower parts pale olive- 
yellowish, more decidedly olivaceous 
on breast; edge of wing dull ochra- 
ceous or fulvous. W^ing 2-60-2*80 
(2*72) inches, tail 2-40-2-55 (2*49), 
culmen 0'58-0 - 60 (0 - 59), width of 
bill at base 0-25, tarsus 0-65-0*70 
(0-68).— Hab. Southern and Eastern 
Mexico (Oaxaca, Cordova, Mirador, 
&c.) . . . E. bairdii. 
h 2 . Above bright olive or olive-green. 
i 1 . Above bright olive-green, the 
wing-bands similar but paler, 
sometimes inclining to ochra- 
ceous; lower parts greenish sul¬ 
phur-yellow, distinctly shaded 
