strongly convex and prominent basally, faintly convex and ascending terminally. Nostril exposed, small, longitudinally broadly oval, margined above by a narrow extension of the membraneous integument of nasal fossa, an internal tubercle showing conspicuously in posterior portion. No trace of rictal bristles, and feathers of chin without terminal setæ. Wing moderate, very much rounded, but longest primaries extending decidedly beyond secondaries; sixth and seventh, fifth and sixth, or fourth, fifth, and sixth primaries longest, the tenth (outermost) between one-half and three-fifths as long as the longest, the eighth slightly longer, the ninth decidedly shorter, than secondaries. Tail about four-fifths as long as wing, much rounded (graduation not greater than length of culmen), the rectrices (12) broad, rounded terminally. Tarsus about two-fifths as long as wing, rather slender, the acrotarsium distinctly scutellate, the planta fused (sometimes indistinctly scutellate on outer side); middle toe, with claw, much shorter than tarsus, but decidedly longer than whole cuhnen; outer toe, without claw, reaching to or slightly beyond middle of subterminal phalanx of middle toe, the inner toe slightly shorter; hallux shorter than inner toe but much stouter; basal phalanx of middle toe wholly or for much the greater part united to outer toe, about half united to inner toe; claws moderate in size and curvature, that of the hallux decidedly shorter than the digit. Plumage full and blended, that of rump and flanks more lengthened and lax; loral, rictal, and orbital regions — sometimes forehead and crown also — naked, the crown with sparse hair-like feathers or bristles.
Coloration. — Adult males uniform black, -the wing-coverts (at least some of the lesser coverts) tipped with white, the back sometimes with a small concealed patch of white; adult females and young males brown above, tawny or rufescent below; bare skin of head light blue in life (in both sexes).
Range. — Honduras to Colombia. (Two species.)
KEY TO THE SPECIES AND SUBSPECIES OF GTMNOCICHLA.
a. General color black. (Males.)
- b. Forehead, lores, and more or less of crown nude. (Adult males.)
- c. Anterior margin of lesser wing-covert area mostly black; bill black. (Gymnocichla nudiceps.)
- d. Deeper black, the posterior under parts black; smaller under wing-coverts mostly wholly black.
- e. Smaller (averaging: wing 76.4, tail 57.7, culmen 20.6, tarsus 29.4). (Eastern Panamá and adjacent parts of northwestern Colombia.)
- d. Deeper black, the posterior under parts black; smaller under wing-coverts mostly wholly black.
- c. Anterior margin of lesser wing-covert area mostly black; bill black. (Gymnocichla nudiceps.)
- ee. Larger (averaging: wing 78.9, tail 61.7, culmen, 20.9, tarsus 30). (Northwestern Panamá and western Costa Rica.)
