52 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



PENELOPINA NIGKA NIGRA (Eraser) 



Guatemalan Black Chachalaca 



Adult male. — Forehead, crown, occiput, cheeks, auriculars, nape, sides 

 of neck, entire upperparts, wings and tail, and lower throat and upper 

 breast black with a dark bluish to greenish gloss,^^ darkest on the head, 

 becoming somewhat greenish on the scapulars, wings, back, and tail ; 

 lower breast, abdomen, sides, flanks, and under tail coverts dark fuscous- 

 black, the sides and under tail coverts with a blue-green sheen; under 

 wing coverts like the upper ones; chin and upper throat bare and red 

 in color; circumocular area purplish; iris dark brown; bill and feet red. 



Adult female. — Forehead, crown, occiput, and nape dark fuscous, each 

 feather narrowly edged with Brussels brown to Argus brown; sides of 

 head, auriculars, sides of neck, lower throat, and upper breast fuscous 

 indistinctly barred with Brussels brown; interscapulars, inner, lesser, and 

 median upper wing coverts banded narrowly with fuscous-black and 

 Argus brown, the two colors present in about equal widths ; back, lower 

 back, and rump similar but paler and duller — pale, rather olive-brown 

 and Brussels brown; scapulars, remiges, and outer and greater upper 

 wing coverts dark fuscous-black with an oily greenish gloss and crossed 

 with numerous narrow Brussels-brown bands, these bands narrower than 

 the darker interspaces and restricted to the outer webs of all the remiges 

 except the innermost secondaries and much reduced even on the outer web 

 toward the tips of the feathers, the under surface of the wing being uni- 

 form fuscous-black; upper tail coverts olive-brown with irregular, fairly 

 broad cross bars of blackish and Argus brown; central pair of rectrices 

 bright Argus brown barred with fuscous-black, the bars not quite so wide 

 as the interspaces, there being about 20-25 dark bars on the median rec- 

 trices, these bars tending to break up laterally toward the tip of the 

 feather; the other i-ectrices similar but with an increasing restriction of 

 the Argus brown to the outer webs, and with a narrowing of the same 

 (widening of the fuscous-black areas) toward the tip; lower breast, ab- 

 domen, sides, flanks, and under tail coverts grayish buffy brown, darkening 

 posteriorly to Saccardo's umber on the thighs and under tail coverts, and 

 the feathers more or less marked with irregular, wavy pale bars of pale 

 buflfy to buffy whitish, these bars edged narrowly with dusky. ^^ 



Juvenal male. — Above similar to adult female but with the rectrices 

 different, not Argus brown barred with black, but blackish with two 

 pairs of longitudinal, wavy, interrupted, narrow streaks of brownish, one 

 pair next to the shaft (one on each side) and one pair slightly nearer 

 the outer than the inner edge of each weh, this pair confluent about 



" There may be some seasonal variation in the bluish or greenish sheen. 

 °' In older birds the ventral barring is restricted to thighs, flanks, and under tail 

 coverts ; in younger birds mpre pf the underparts generally are affected. 



