BASILEUTEETJS. 173 



In 1873 the Costa-Rica form of this Badleuterus was separated from B. uropygialis 

 under the name of B. leucopygius \ as it was then thought to be sufladently different 

 from the Panama bird to warrant the distinction. A reexamination of the types now 

 convinces us that one of the chief differences relied upon, the pale colour of the rump, 

 is due to the worn and faded state of the specimens ; so that we are driven to the 

 conclusion that the Costa-Rica and Panama birds belong to the same species. For 

 this we retain the somewhat inappropriate name Badleuterus leucopygius, for the 

 reasons stated below. 



This bird was first known as an inhabitant of Central America from specimens 

 obtained by M'Leannan and Galbraith 2. These were called B. semicermnus of Sclater 

 by Mr. Lawrence, an identification that was subsequently questioned, as the birds were 

 supposed to agree better with B. uropygialis of the same author ^. As some confusion 

 exists relative to these two species, we propose briefly to examine them. 



The description of B. semicervinus was based upon specimens obtained near Nanegal 

 in Western Ecuador by Eraser *. We have since received examples from Santa Rita, 

 on the same side of the Andes of Ecuador; and we have also others, of Salmon's 

 collecting, from Remedies in the Cauca valley, Colombia, which are correctly referred 

 to B. semicervinus f. It would thus appear that B. semicervinus is a bird of Western 

 Ecuador, extending northwards, as is so frequently the case in birds of that district, into 

 the Cauca valley. 



Basileuterus uropygialis was described from a specimen with the vague locality 

 " Brazil " attached to it J. This bird we now recognize in specimens from Sarayacu in 

 Eastern Ecuador, Chyavetas in Peru §, and Bogota, the latter probably obtained in the 

 upper valley of the Meta. Thus it appears that each of these birds has a very distinct 

 range, separated by the Andes. Their differences are described in, and both birds are 

 figured on a plate accompanying, a synopsis of the species of Basileuterus, published by 

 Mr. Sclater in 1865 ||. It will there be seen that B. semicervinus has a darker back, 

 and the underparts strongly tinged with fawn-colour, whereas B. uropygialis has an 

 olive back, and usually pale underparts. 



Now, on reconsidering the position of the Central- American bird, we are of opinion 

 that it comes nearest to the bird of Western Ecuador, B. semicervinus, rather than that 

 of the upper valleys of the basin of the Amazons, B. uropygialis. 



But as the present bird has the feathers of the breast more or less edged with brown, 

 and the sides of the neck and flanks not nearly so clear a fawn-colour as in B. semi- 

 cervinus, but decidedly browner, we keep B. leucopygius under a distinct name. At 

 the same time we admit that the relationship with B. semicemnus is very close, and 

 recognize the justice of Mr. Lawrence's first application of this name to the Panama 

 bird. 



* Sel. P. Z. S. 1860, p. 84. t Scl. & Salv. P. Z. S. 1879, p. 494. t Sol. P. Z. S. 1861, p. 128. 



§ Scl. & Salv. P. Z. 8. 1873, p. 257. |l P. Z. S. 1865, p. 282 et se^., 1. 10. 



