794 Annals of the Carnegie Museum. 



This interesting warbler is found over the whole of the Caribbean foot- 

 hills and upper part of the lowlands, ranging from about 500 to 2,000 feet; 

 also on the Pacific slope from the Rio Grande de Tarcoles northward, in- 

 cluding the whole of Nicoya and Guanacaste, at about the same altitudes. 

 It is always found along the margins of little streams flowing through the 

 forest, where it feeds among the rocks and along the banks. The birds 

 have the peculiar habit of constantly raising and lowering the tail as they 

 stand or hop from rock to rock, and are very shy and hard to approach 

 within shooting range. 



588. Basileuterus semicervinus veraguensis (Sharpe). 



Basileidcrus leucopygius subsp. «. Basileuterus veraguensis Sharpe, Cat. Birds 

 Brit. Mus., X, 1885, 403 (Paraiso Station, Panama R.R.; coll. Brit. Mus.). 



Basileuterus veyaguensis Cherrie, Expl. Zool. en C. R., 1891-2, 1893, 14 (Boruca 

 and Buenos Aires); Expl. en el Rio Naranjo, 1893, 12 (Rio Naranjo; habits; 

 song; crit.). 



Basileuterus semicervinus veraguensis Ridgway, Birds N. and Mid. Amer., II, 

 1902, 756 (Isthmus of Panama, northward to southwestern Costa Rica: Rio 

 Naranjo, Boruca, and Buenos Aires). — Bangs, Auk, XXIV, 1907, 306 (Bo- 

 ruca and Paso Real de Terraba [Underwood]; critical). 



Bangs Collection: El General and Buenos Aires de Terraba, Pozo Azul 



de Pirris (Underwood). 

 Carnegie Museum: Paso Real, Boruca, Buenos Aires de Terraba, Pozo 



Azul de Pirris (Carriker). Seven skins. 



Costa Rican specimens exhibit a considerable amount of variation, 

 some being typical veraguensis and others coming near to leucopygius, due, 

 I suppose, to the close proximity of the ranges of the two subspecies, which 

 in this intermediate area tend to intergrade. In spite of this variation 

 I think that all specimens taken from the Pirris Valley, southward, may 

 be referred without question to the southern race. 



The habits and habitat of the two races is exactly the same, so far as I 

 observed. 



589. Basileuterus culicivorus culicivorus (Lichtenstein). 



Sylvia culicivora Lichtenstein, Preis-Verz. Mex. Vog. 1830, 2, no. 78 (Mexico, 

 see Jour, fiir Orn., 1863, 67). 



Basileuterus culicivorus Cabanis. Mus. Hein., I, 1850, 17 (Jalapa, Mexico). — 

 Baird, Rev. Am. Birds, 1865, 245 (Barranca, Costa Rica, Mar. 17, 1864 

 [Carmiol]). — Lawrence, Ann. Lye. N. Y., IX, 1868, 95 (Barranca and 

 Guaitil [J. Carmiol], Grecia and Dota (?) [F. Carmiol]). — Frantzius, Jour, 

 fiir Orn., 1869, 294 (Costa Rica). — Boucard, P. Z. S., 1878, 52 (San Jose). 

 — Salvin and Godman, Biol. Centr.-Am., Aves, I, 1881, 171, part (Costa 

 Rican references). — Sharpe, Cat. Birds Brit. Mus., X, 1885, 383, part 



