Carriker : List of the Birds of Costa Rica. 671 



Hondura, Bebedero, El Hogar, Miravalles (Carriker). Seven 



skins. 



The question of identifying the specimens of Attila from Costa 

 Rica has always been a puzzling one, and unfortunately (so far as I 

 can determine) Mr. Ridgway has only complicated matters in his 

 treatment of the genus, at least that portion supposed to occur within 

 the limits of Costa Rica. After the most careful study of a large 

 series of skins of A. citreopygus (twenty-four from Costa Rica, eight 

 from Panama, and one from Honduras), the only conclusion I can 

 reach is that there is but one form of that species to be found within 

 the limits of Costa Rica, and that A. citreopygus luteolus Ridgway 

 cannot be recognized as distinct from true citreopygus. 



This species has a very wide range in Costa Rica, covering prac- 

 tically the whole of the country up to at least 6,000 feet above sea- 

 level (I saw a specimen near La Palma at not less than 6,000 feet), 

 not only on the eastern and western slopes, but over the central 

 plateau region as well. Among birds from the same locality, taken 

 at the same time, will be found a great amount of variation. The 

 young birds are much darker brown above and have a brownish breast, 

 but even among immature birds will be found the pale phase which 

 Mr. Ridgway has named luteolus, well illustrated by two skins, one 

 from Carrillo and the other from Cariblanco de Sarapiqui (two locali- 

 ties with almost the same altitude and identical conditions present), in 

 which one bird has the usual brown breast and the other a very pale 

 one, with the remainder of the plumage corresponding. These two 

 localities are on the Caribbean slope, low down, while the supposed 

 range of luteolus is the Pacific slope. In the series examined there 

 are five adults corresponding to the phase of plumage called luteolus 

 by Mr. Ridgway, one from El Pozo de Terraba, two from Bolson, 

 one from Miravalles, and one from La Vijagua. In all of these locali- 

 ties specimens were taken in the ordinary plumage of citreopygus, 

 while La Vijagua is on the Caribbean watershed. 



Again, Attila citreopygus has a continuous range from Nicaragua to 

 Panama, so that if A. c. luteolus is recognized, what can be given as 

 its range ? It is found in the middle of the range of another bird only 

 subspecifically distinct from it, and in company with that bird, which 

 according to the definition of a subspecies, is an impossibility. There- 

 fore, taking all these facts into consideration I do not see how it can 

 be recognized, and have, accordingly, placed all references to it un- 



