Carriker : List of the Birds of Costa Rica. 613 



Carlos). — Zeledon, An. Mus. Nac. de C. R., I, 1887, 115 (Pacuare, Pozo 

 Azul de Pirris and Jimenez). — Salvin and Godman, Biol. Centr.-Am., Aves, 

 II, 1892, 214, part (Costa Riean references). — Cherrie, Expl. Zool. en 

 C. R., 1890-1, 1893, 42 (Lagarto, Boruca, Terraba, and Buenos Aires). — 

 Underwood, Ibis, 1896, 440 (Miravalles). 



Cercomacra crepera Bangs, Auk, XVIII, 1901, 365 (Divala, Chiriqui, Panama). 



Cercomacra tyrannina crepera Bangs, Auk, XXIV, 1907, 296 (Boruca, El Pozo, 

 Paso Real, and Barranca de Terraba [Underwood]). — Carriker, Ann. 

 Carnegie Museum, V, i, 1908, 8 (Bebedero, Pozo Azul de Pirris, El Pozo de 

 Terraba, Boruca, and Buenos Aires; critical). 



U. S* Nat. Museum: Talamanca (Cherrie), Jimenez (Alfaro), Pozo 



Azul de Pirris (Underwood), Pigres (Ridgway and Zeledon). 

 Bangs Collection : Pozo Azul de Pirris, Carrillo, Cerro de Santa Maria, 



Tenorio, La Vijagua El General de Terraba (Underwood). 

 C. H. Lankester Collection : Guacimo. 



Fleming Collection : Pozo Azul de Pirris, Carrillo, Miravalles (Under- 

 wood). 

 Carnegie Museum : (see references under C. t. crepera, Ann. Carnegie 

 Museum, V, i, 1908, 8). Thirty-two skins. 



Costa Rican specimens of this species vary a great deal in the in- 

 tensity of the coloration, especially in the males, those from the Carib- 

 bean slope and from northwestern Costa Rica being much darker 

 than those from the southwestern region. In fact some of the birds 

 from Terraba are almost as pale as some of the Colombian speci- 

 mens of true C. tyrannina. I should call the Caribbean birds typical 

 of C. t. crepera (although the bird was described from the Pacific 

 side of Chiriqui), and those from the Terraba district more or less in- 

 termediate between C. t. tyrannina and C. t. crepera, but nearer to 

 the latter, making all Costa Rican specimens referable to the dark 

 race. 



This is the most abundant of all the Formicariidce, in Costa Rica, 

 being found over the whole of the Caribbean lowlands up to about 

 1,500 feet and the Pacific lowlands up to 2,000 feet. They are rarely 

 seen in the heavy dark forest, but inhabit the more open woodland 

 where the undergrowth is very dense, and patches of wild cane along 

 the river banks. They are always seen in pairs, are very tame, and 

 are always appearing in most unexpected places ; thereby making them- 

 selves a great nuisance to the collector, who frequently mistakes them 

 for something else, until after he has shot them. 



