72 PROCEEDINGS OF THE ACADEMY OF 



fide ejusd. Cat.). Bahia (Bryant, Mus. S. I.). Brazil (Mus. L. 

 Agassiz). 



Obs. The ordinary South American Myiarchus is distinguished 

 at a glance from all the foregoing by the reduction of the rufous 

 edging of the rectrices and primaries to a mere trace, or its entire 

 absence. 



This bird averages a little smaller than crinitus; the bill is 

 shaped and colored exactly as in that species, but is rather 

 smaller ; the wings are shorter, both absolutely and relatively, not 

 often quite equalling the tail; the tarsi, on the contrary, are a 

 little longer. In these respects the bird tallies to a nicety with 

 cinerascens. 



The colors are rarely if ever as bright and clear as in crinitus. 

 There is generally a mere trace of rufous on the outer edges of the 

 primaries and rectrices, and in younger birds is quite noticeable; 

 but I have never seen a touch of it on the inner webs of the rec- 

 trices. The outer edges of the wing coverts and inner remises, 

 and the outer edges of the outer rectrices. and the inner edges of 

 the remiges, are whitish or pale yellowish ; otherwise the wings 

 and tail are concolor and unicolor. 



With both Mr. Lawrence's types, a typical Brazilian swainsoni 

 labelled in Dr. Sclater's handwriting, and various unquestionable 

 ferox before me, I cannot distinguish even a geographical variety 

 among them all. The} 7 are indisputably identical. 



Swainsoni is one of those constant!}' recurring cases of the 

 attempt to distinguish Brazilian individuals from specimens of the 

 same species from northern South America. Sometimes, I know, 

 local influences have produced modifications recognizable as geo- 

 graphical varieties, and I am willing to admit in this case that 

 swainsoni may run a shade darker, and possibty average a trifle 

 larger than ordinary ferox; but the difference is not even tangible, 

 much less reasonably constant. Birds from either locality differ 

 as much among themselves as they do from each other; and some 

 specimens of swainsoni are more like ferox than they are like 

 other specimens of swainsoni. 



Panamensis, as originally described, was compared with crinitus 

 and cinerascens, and its striking differences correctly indicated. 

 But I am persuaded that if Mr. Lawrence had compared it with 

 ferox, he would have been satisfied of its identit}' with the latter. 



Venezuelensis is based upon a youngish bird, which, as usual 



[July 2, 



