98 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



strongly convex and prominent basally, faintly convex and ascending 

 terminally. Nostril exposed, small, longitudinally broadly oval, mar- 

 gined 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 setse. 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 sliglitly 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 culmen; outer 

 toe, without claw, reacliing to or slightly beyond middle of subter- 

 minal 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 GYMNOCICHLA. 



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. (Gymno- 

 cichla 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). (East- 

 ern Panama and adjacent parts of northwestern Colombia.) 



Gjminocichla nudiceps nudiceps, adult male (p. 99). 

 ee. Larger (averaging: wing 78.9, tail 61.7, culmen, 20.9, tarsus 30). (North- 

 western Panamd. and western Costa Rica.) 



GymnocicMa nudiceps erratilis, adult male (p. 101). 



