K\\<;> \\i> PENARD; NOTES ON AMERICAN BIRDS. 'Ml 



Remarks. Ilcrlepseh (Proc. [ntern. orn. congressj 1W7, p. 478) 

 also has called attention to the Fad that M. semirufvs did nol belong 

 in Myiarchus. 



THE FORMS OF TYRANNUS MELANCHOLICUS VIEILLOT. 



This wide-ranging species inhabits a vast area from the Lower Rio 

 Grande in Texas, south to Argentina, and throughout its range is 

 locally common. According to Chapman (Bull. Amer. mus. nat. hist., 

 1917, 36, p. 478) it is in the main a bird of the tropical zone, but ap- 

 parently follows the trails and clearings up into the mountains, being 

 found even on the Bogota Savanna at an altitude of 8,750 feet. 



The species varies very little, especially within its South American 

 range. One of the distinguishing characters usually ascribed to birds 

 from northern South America, is the paler color of the back, but we 

 find this very unreliable. In freshly moulted birds from all parts of 

 the range of the species, the upper parts are olive greenish, while in 

 birds in worn, post-breeding plumage, the back is often faded to a dull 

 gray color with practically no olive tone. On the whole, however, 

 birds from southern South America, true T. m. melancholicus, are a 

 trifle darker than those from northern South xAmerica. 



We have been confronted by the usual unreliability in regard to sex 

 determinations in species the males and females of which are similarly 

 colored; for if, as is generally supposed, the male of this species is 

 larger than the female, many of the specimens have been wrongly 

 sexed by collectors. After examining much material, we have decided 

 to ignore the sex marks on the labels altogether, although disposed to 

 regard the smaller specimens of each form as females. 



In comparing a very large number of specimens from various parts 

 of Central and South America, we distinguish fixe forms, of which the 

 characters and geographical distribution are as follows: — 



1. TYRANNUS MELANCHOLICUS MELANCHOLICUS Yieillot. 



Tyrannus melancholicus Yieillot, Nbuv. diet., 1819, 35, p. 84 (Paraguay). 

 Type. — ? Mus. hist. nat. Paris. 



Subsfecific characters. — A large form. Chest-band wide and rather 

 dark, Buffused more with gray than with yellow; head dark gray; throat gray, 

 not white. 



