- dd. Duller black, the posterior under parts blackish slate; smaller under wing-coverts broadly tipped with white. (Coast district of northeastern Colombia.)
- cc. Anterior margin of lesser wing-covert area broadly white; bill whitish or light yellowish. (Eastern Costa Rica to eastern Guatemala.)
- bb. Forehead, lores, and crown feathered. (Immature males.)[2]
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)
- cc. Slightly darker and larger (wing averaging 75.1, tail 59.3, culmen 19.9, tarsus 29.4)
- bb. Wing-coverts blackish, broadly tipped with bright tawny.
GYMNOCICHLA NUDICEPS NUDICEPS (Cassin).
BAKE-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, alulæ 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).[4]
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-martæ 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-martæ not seen by me.
- ↑ Eight specimens.
