BIRDS OF NORTH AND MIDDLE AMERICA 99 
dd. Duller black, the posterior under parts blackish slate; smaller under wing- 
coverts broadly tipped with white. (Coast district of northeastern 
Colombia.) 
Gymnocichla nudiceps sancta-marte, adult male (extralimital).¢ 
ce. Anterior margin of lesser wing-covert area broadly white; bill whitish or light 
yellowish. (Eastern Costa Rica to eastern Guatemala.) 
Gymnocichla chiroleuca, adult male (p. 101). 
bb. Forehead, lores, and crown feathered. (Immature males.) 6 
aa. General color brown above, deep tawny below. (Adult females.) 
b. Wing-coverts brown, indistinctly tipped with rufous-tawny. (Gymnocichla 
nudiceps.) 
c. Slightly paler and smaller (wing averaging 73.6, tail 55.4, culmen 19.7, tarsus 
29:2) sieiscarsaniemisusdiaiecos Gymnocichla nudiceps nudiceps, adult female (p. 99). 
ce. Slightly darker and larger (wing averaging 75.1, tail 59.3, culmen 19.9, tarsus 
29 A os. Mxtereoeend Gymnocichla nudiceps erratilis, adult female (p. 101).¢ 
bb. Wing-coverts blackish, broadly tipped with bright tawny. 
Gymnocichla chiroleuca, adult female (p. 102). 
GYMNOCICHLA NUDICEPS NUDICEPS (Cassin). 
BARE-CROWNED ANTBIRD. 
Adult male-—Uniform black, slightly duller on rump, upper tail- 
coverts, and posterior under parts, the latter inclining to slate-black; 
all the wing-coverts margined terminally with white, alule and outer- 
most primary edged with white, and rectrices (except middle pair) 
narrowly tipped with white; smaller under wing-coverts uniform 
black, the under primary coverts slate color or slate-gray, broadly 
margined with white; inner webs of remiges broadly edged with pale 
gray or grayish white; naked skin of head bright light blue in life; 
bill black; iris brown; legs and feet horn color or dusky (bluish gray 
or grayish blue in life?); length (skins), 143-157 (152); wing, 73.5— 
80.5 (76.1); tail, 54-60 (57.1); culmen, 19.5-21.5 (20.6); tarsus, 
28.5-30.5 (29.6); middle toe, 18-20.5 (18.9).¢ 
Immature male(= Myrmelastes corvinus Lawrence and M. ceterus 
Bangs).—Similar to the adult male but whole pileum feathered (only 
the loral and orbital regions being naked) and greater wing-coverts 
wholly dark sooty brown or sooty black (without white tips). 
Adult female-—Above plain olive-brown, russet-brown or mummy 
brown, the wings more rufescent (chestnut-brown), with tips of wing- 
coverts (rather broadly) deep cinnamon-rufous, rufous-chestnut or 
deep tawny; tail dark russet-brown or vandyke brown, the rectrices 
(except middle pair) sometimes (usually ?) narrowly tipped with pale 
@ Gymnocichla nudiceps sancta-marte Ridgway, Proc. Biol. Soc. Wash., xxi, Oct. 20, 
1908, 194 (Santa Marta, Colombia; coll. U. S. Nat. Mus.). 
> The different forms distinguished by same characters as those given for adult 
males (c to cc). 
¢ The adult female of G. nudiceps sancta-martx not seen by me. 
¢ Eight specimens. 
