BIRDS OF NORTH AND MIDDLE AMERICA. 101 



Myrmelask's ceterus Bangs, Proc. New Engl. Zool. Club, ii, Sept. 20, lUOO, 25 



(Loma del Leon, i. e., Limi Hill, Panama; coll. E. A. and 0. Bangs). 

 [Myrmelastcs] ceterus Sharpe, Hand-list, iii, 1901, 32. 



GYMNOCICHLA NUDICEPS ERRATILIS Bangs. 



COSTA mCAN BARE-CROWNED ANTBIRD. 



Similar to G. n. nudiccps but averaging slightly larger, the adult 

 female averaging more intense in coloration." 



Adult male.— Lengili (skins), 147-163.5 (153.5); wing, 75.5-83 

 (78.9); tail, 59.5-64.5 (61.7); exposed cnlmen, 20-22 (20.9); tarsus, 

 29.5-30.5 (30); middle toe, 19-20 (19.4).'' . 



Adult female .—ljQ\\g{\\ (skins), 137.5-153 (148); wing, 72.5-77.5 

 (75.1); tail, 56-02 (59.3); exposed culmen, 19-21 (19.9); tarsus, 

 29-30 (29.4); middle toe, 18-19.5 (18.9).^ 



Southwestern Costa Rica (Boruca; Pozo del Rio Grande, Boruca; 

 Terraba; Paso Real de Terraba; Buenos Aires; El General; Pigres), 

 and northwestern Panama (Divala;"^ Mina de Chorcha; Bugaba; 

 Chitra) ? 



(?) Gymnocichla nudiceps (not Myiothera nudiccps Cassin?) Salvin, Proc. Zool. Soc. 



Lond., 1870, 195, part (Mina de Chorcha and Bugaba, Veragua, Panama; 



crit.). — ScLATER, Cat. Birds Brit.Mus., xv, 1890, 272, part (Mina de Chorcha, 



Bugaba, Chiriqui, and Chitra, Panama). — Salvin and Godman, Biol. Centr.- 



Am., Aves, ii, 1892, 223, part (Chiriqui, Bugaba, Minade Chorcha, and Chitra, 



Panama) . 

 Gymnocichla nudiceps (not Myiothera nudiceps Cassin) Cherrie, Expl. Zool. Merid. 



Costa Rica, 1893, 42 (Boruca, Terraba, and Buenos Aires, s. w. C'osta Rica; 



crit.). 

 GymnocicJila nudiceps erratilis Bangs, Auk, xxiv, no. 3, July, 1907, 297 (Boruca, 



s. w. Costa Rica; coll. E. A. and O. Bangs). — Carriker, Ann. Carnegie 



Mus., vi, 1910, 020 (Costa Rica; crit.; habits). 



GYMNOCICHLA CHIROLEUCA Sclater and Salvin. 



BARE-FRONTED ANTBIRD. 



Similar to G. nudicejys but adult male with bend of wing white 

 and white tips to wing-coverts broader, much less of concealed white 

 on back, and bill paler (plumbeous in life, whitish — at least termi- 

 nally — in dried skins) ; adult female wdth wing-coverts very much 

 darker, contrasting much more strongly with their tawny or rufescent 

 tips. 



Adult male. — General color uniform black; bend of wing, broad 

 tips to all the wing-coverts, and broad edging to outermost feather 

 of alula and outermost primary, white; feathers of anterior portion 



o The diff-^rence in coloration of temales is by no means constant, but the average 

 difference is very obvious. 



t'Ten specimens. 



'' Having only adult males from that locality, I am not able to determine whether 

 specimens of this species from Divala belong to the present form or true G. nudiceps. 

 No specimens from other localities in Chiriqui have been seen by me. 



