BIRDS OF NORTH AND MIDDLE AMERICA. 97 



(Coban, Guatemala; Belize); Proc. Zool. Soc. Lend., 1870, 837 (San Pedro, 

 Honduras). — Salvin and Sclater, Ibis, 1860, 36 (Yzabdl, Guatemala). — 

 Salvin, Proc. Zool. Soc. Lend., 1867, 145 (Santa Fe de Verdgua, w. Panama); 

 1870, 195 (Mina de Chorcha and Bugaba, w. Panamd). — Lawrence, Ann. 

 Lye. N. Y., ix, 1868, 109 (Angostura, Costa Rica). — Frantzius, Journ. 

 fur Orn., 1869, 305 (Costa Rica).— Boucard, Proc. Zool. Soc. Lond., 1878, 

 61 (San Carlos, Costa Rica); Ann. Soc. Linn. Lyon, 1878, 39 (Guatemala). — 

 Nutting, Proc. U. S. Nat. Mus., vi, 1883, 386 (Sucuya, Nicaragua), 405 

 (Los Sabalos, Nicaragua). — Zeledon, Anal. Mus. Nac. Costa Rica, i, 1887, 

 115 (Pacuare, Jimenez, and Pozo Aziil, Costa Rica). — Salvin and Godman, 

 Biol. Centr.-Am., Aves, ii, 1892, 214, part (Playa Vicente and Sochiapa, 

 Vera Cruz; Belize, Brit. Honduras; Chisec, etc., Guatemala; San Pedro, 

 Honduras; Matagalpa, etc., Nicaragua; Tucurriqui, etc., Costa Rica; Bugaba, 

 Mina de Chorcha, and Santa Fe de Veragua, Panama). — Richmond, Proc. 

 U. S. Nat. Mus., xvi, 1893, 501 (Rio Escondido, Nicaragua; habits).— 

 Cherrie, Expl. Zool. Merid. Costa Rica, 1893, 42 (Lagarto, Boruca, Terraba, 

 and Buenos Aires, s. w. Costa Rica). — Underwood, Ibis, 1896, 440 (Volcan 

 de Miravalles, Costa Rica). 



[Cercomaa-a] tyrannina Sclater and Salvin, Nom. Av. Neotr., 1873, 73, part. — 

 Sharpe, Hand-list, iii, 1901, 28, part. 



Cercomacra tyrannina tyrannina Carriker, Ann. Carnegie Mus., v, no. 1, Oct. 

 1, 1908, 9, in text (s. w. Costa Rica). 



Cercomacra crcpcra Bangs, Auk, xviii, Oct., 1901, 365 (Divala, Chiriqui, Panamd; 

 coll. E. A. and 0. Bangs).— Dearborn, Pub. 125, Field Mus. Nat. Hist., 

 1907, 109 (Los Amates, e. Guatemala; crit.). 



Cercomacra tyrannina crepera Bangs, Auk, xxiv, 1907, 296 (Boruca, Paso Redl, 

 Pozo del Rio Grande, and Barranca, s. w. Costa Rica). — Carriker, Ann. 

 Carnegie Mus., v, 1908, 8 (e. Costa Rica; crit.); vi, 1910, 612 (Costa Rica; 

 crit.; habits).— Ferry, Pub. 146, Field Mus. N. H., orn. ser., i, no. 6, 1910, 

 271 (Guayabo, Costa Rica). 



Genus GYMNOCICHLA Sclater. 



Gymnocichla Sclater, Proc. Zool. Soc. Lond., 1858, 274. (Type, Myiothera 

 nudiceps Cassin.) 



Medium-sized Formicariidffi (length about 140-160 mm.) resem- 

 bling the larger and stouter species of Myrmeciza, but with bill 

 weaker, less compressed anteriorly and less strongly uncinate, the 

 culmen less distinctly ridged; nostril smaller; relatively shorter tarsus 

 (only two-fifths as long as wing), with acrotarsium distinctly scutel- 

 late; tail shorter (not more than four-fifths as long as wing), the 

 adult males with loral and suborbital regions (sometimes whole 

 pileum) naked. 



Bill about as long as head, narrowly wedge-shaped in vertical 

 profile (with nearly straight lateral outlines), its width at posterior 

 end of nostrils about equal to its depth at same point and equal to a 

 little less than half the distance from nostril to tip of maxilla; culmen 

 slightly ridged, straight to near tip where abruptly decurved, the 

 point of maxilla slightly or minutely uncinate; tomium straight, with 

 small subterminal notch, that of the mandible less distinct; gonys 



81255°— Bull. 50—11 7 



