BIRDS OF NORTH AND MIDDLP: AMERICA. 179 



Bill loiig-er than head, elongate-conical, acute, ('ompressed, with 

 nearl}' straight outlines, its basal depth decidedly less than distance 

 from nostril to tip of maxilla, its basal width less than half that dis- 

 tance ; culmen straight, ascending but not conspicuously elevated 

 basally, forming a broad, nearly flat, frontal shield, with rounded pos- 

 terior outline, the extreme posterior portion of which extends about 

 as far as the anterior angle of the eye; gonys straig"ht, decidedl}^ more 

 than half as long as culmen, but about as much shorter than distance 

 from nostril to tip of maxilla; mandibular rami widened, but not 

 swollen, posteriorly, with terminal outline truncate or faintly concave; 

 commissure nearly straight. Nostril much below lateral median lino 

 of maxilla, small, broadly oval or nearly circular, bore4 directly into 

 the horny rhinotheca, beveled ofl' anteriorh% posteriorly touching the 

 loral feathering. Wing moderate (more than three times as long as 

 culmen), short-tipped (primaries exceeding secondaries by less than 

 length of culmen), rounded; outermost (ninth) primary intermediate 

 between fifth and fourth; seventh, or seventh and sixth, longest; four 

 outer primaries broad and rounded at tips (the first slightly contracted 

 terminally), their inner webs faintly sinuated. Tail about three- 

 fourths as long- as wing, graduated, with middle pair of rectrices 

 abruptly abbre^'iated (intermediate in length between outermost and 

 the next), the rectrices rather narrow, but not obviously contracted 

 terminally nor pointed. Tarsus about as long as the maxilla from 

 nostril, or a little longer, stout, its anterior scutella ver}' distinct; 

 middle toe, with claw, about as long as tarsus; outer toe with claw 

 reaching about to base of middle claw, the inner slightly shorter; 

 hallux shorter than lateral toes, l)ut conspicuously stouter, its claw 

 slightly shorter than the digit; all the claws strongh' curved. A 

 crescentic patch inunediately ])ehind frontal shield, rictal and sub- 

 orbital regions, anterior and middle portion of malar region, and sides 

 of chin and throat naked, the last separated from the naked cheek- 

 space by a narrow line of feathering; a sparse crest of narrow elon- 

 gated feathers springing from middle of crown. 



Coloration. — Black and chestnut, or yellowish olive-green, with tail 

 mostly yellow. 



Range. — Southern Mexico to Bolivia and southern Brazil. (Five 

 species, only one of them north of the Isthuuis of Panama.) 



KEY TO THE (SPECIES OF GYMNOSTIXOPiS. 



n. Wings, upper tail-coverts, and flanks chestnut. 



h. Breast, abdomen, and thighs chestnut. (Southern Mexico tolsthrausof Panama. ) 



Gymnostinops montezuma (p. 180) 

 hh. Breast, abdomen, and thighs black. (Northern Colombia.) 



Gymnostinops cassini (p. 181) 



n.<t. Wings (except a small area next to scapulars), upj)er tail-coverts, and flanks 



black. (Northern Colombia. ) Gymnostinops guatimozinus (p. 182) 



