206 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
mandible then recurved or subfalcate), the extreme tip sometimes 
slightly decurved; gonys gently convex, strongly ascending terminally, 
more strongly convex and sometimes rather prominent basally. 
Nostril exposed, posteriorly in contact with loral feathering, very 
small, broadly oval or roundish, non-operculate, but margined above 
by a very narrow concave membrane. Rictal bristles wanting, and 
feathers of chin, etc., without terminal sete. Wing moderate, rather 
pointed, the longest primaries exceeding secondaries by less than 
length of bill from nostril to more than length of exposed culmen; 
sixth and seventh, sixth, seventh, and eighth, or fifth, sixth, seventh, 
and eighth, primaries longest, the tenth (outermost) between two- 
thirds and three-fourths as long as the longest, the ninth much 
longer than secondaries. Tail four-fifths as long as wing to very 
slightly longer than wing, rounded or graduated (graduation equal 
to from about one-ninth to more than one-third its total length), 
the rectrices (12) subacuminate. Tarsus longer than culmen, less 
than one-fourth to nearly one-third as long as wing, distinctly scutel- 
late; middle toe, with claw, slightly shorter to slightly longer than 
tarsus; outer toe, without claw, reaching to about middle of sub- 
terminal phalanx of middle toe, the inner toe slightly shorter; hallux 
about as long as outer toe but decidedly stouter; basal phalanx of 
middle toe united for much the greater part to outer toe, for at least 
half to inner toe; claws rather large, strongly curved, and acute, that 
of the hallux decidedly shorter than the digit. 
Coloration.—Above brown or olive, the pileum and back sometimes 
narrowly streaked with buffy or whitish, the former usually much 
duller (grayer) or more dusky; upper tail-coverts and tail cinnamon- 
rufous or chestnut; a more or less distinct (usually conspicuous) super- 
ciliary stripe (often an orbital ring also) of buff or ochraceous; under 
parts plain light buffy brown or yellowish brown, paler (yellowish 
or buffy) on throat, or conspicuously streaked or flammulated. 
Sexes alike. 
Range.—Southern Mexico to Peru, Bolivia, southeastern Brazil, 
and Venezuela. (About thirteen species.) @ 
KEY TO THE SPECIES OF XENICOPSIS. 
a. Throat buffy or yellowish, chest light buffy brownish. 
b. Hindneck, upper back, and chest not streaked; upper tail-coverts brown, con- 
color with back; smaller (wing less than 90). 
@ Of these the following have been examined in this connection: X. rufosuper-- 
ciliatus (Lafresnaye), X. oleagineus Sclater, X. subalaris (Sclater), X. percnopterus 
Oberholser, X. variegaticeps Sclater, X. striaticollis (Sclater), X. temporalis (Sclater), 
and X. anzius (Bangs). The last four of these differ from typical Xenicopsis in 
much less graduated tail, relatively much longer wing and shorter tarsus, and 
unstreaked lower parts, and constitute a very well defined group, possibly a distinct 
genus. 
