254 Proceedings of the Biological Society of Washington. 



Description of male. — The male resembles the female in color and in size. 

 Specimens examined. — Micropus peruvianus. Peru: Type locality, 1 d\ 



1 ? ; Huaracondo Canon, 10,000 ft., 1 c?, 1 ?; Torontoy, 8000 ft., 2 9 . 

 Micropus andecolus. Bolivia: Parotani, 8800 ft., Prov. Cochabamba, 



2 cf ; Vinto, 8600 ft., Prov. Cochabamba, 2 c?. Argentina: Tilcara, 8000 

 ft., Prov. Jujuy, 1 cj ; Angaco Sud, 2000 ft., Prov. San Juan, 2 d\ 1 9 ; Men- 

 doza, 1. 



Fig. 1. — Tail of Micropus peruvianus. Fig. 2.- 



(Both natural size.) 



-Tail of Micropus andecolus. 



Remarks. — The type-locality 1 of Cypselus andecolus is the Andes of La 

 Paz, Bolivia. I have no specimens from La Paz, but faunal considerations 

 lead me to believe that four specimens from the Andes at Cochabamba may 

 be accepted as typically representing this bird. That the describers did not 

 mention the buffy tint which characterizes our Bolivian and Argentine 

 specimens is not surprising since it might well be considered as adventitious. 

 While their figure of the species does not therefore show a buffy tint on the 

 white areas, it does show a more deeply forked tail than is exhibited by any 

 of our Peruvian birds, and this in spite of the fact that it is somewhat smaller 

 than natural size. 



Although the characters separating the Peruvian and Bolivian birds 

 seem to me to be of specific value, the birds nevertheless are obviously rep- 

 resentative forms, and it is not probable, therefore, that both would be 

 found at the same locality. If this be true, there can be little doubt of the 

 essential identity of the La Paz and Cochabamba birds. The latter agree 

 minutely with specimens from Argentina, and if my belief that Cochabamba 

 specimens are typical of andecolus is correct, it of course follows that " Apus 

 andecolus dinellii" of Hartert, from Jujuy and Mendoza, Argentina, is a 

 pure synonym of andecolus (Lafr. & d'Orb.). Hartert writes (Bull. B. O. C, 

 XXIII, 1908, p. 43): "The measurements of this species [=di7iellii] are 

 the same as in A. a. andecolus, " indicating that the birds which he identified 

 as andecolus are not the same as the bird from Peru which I here describe. 



iThe type is not in the Museum of Comparative Zoology at Cambridge. 



