428 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



species, and as there is considerable variation in individual series 

 identification is somewhat complicated. For comjjarison with my 

 skins from Paraguay, Uruguay, and Argentina, I have assembled 

 in all a series of 80 specimens from the United States National 

 Museum, the Ameiican Museum of Natural History, the Museum 

 of Comparative Zoologj^, and the Carnegie Museum. On first review 

 it appears that the series may be easily separated into two groups, 

 a northern one ranging from Paraguay northward, in which the 

 dorsal surface is distinctly reddish brown, and a southern one, 

 spread from northern Paraguay and Rio Grande do Sul south- 

 ward, in which the prevailing coloration of the dorsal surface is 

 blackish and gray with little or no brown except in the subspecies 

 tucumanensis, which, however, is distinctly gray. Skins are sub- 

 ject to great seasonal wear, a fact that needs attention as northern 

 specimens in worn breeding dress appear much blacker above than 

 normal. Immature individuals in ju venal plumage are also darker 

 above than normal. There is no appreciable difference apparent in 

 measurements, though a few skins from the Argentine are larger 

 than any examined from farther north. Others, however, have the 

 size identical with skins from elsewhere. The tail is subject to 

 wear and is highly variable in length. 



In this study, as I have been intent on identifying southern skins, 

 I hav^e not attempted to assemble all available specimens from 

 Venezuela and Colombia, and have accepted two northern subspecies 

 in addition to the typical race somewhat on faith. The few skins 

 seen indicate that the forms in question are distinct. Five current 

 subspecies may be recognized as follows : 



1. MYOSPIZA HUMERALIS HUMERALIS (Bosc). 



Tanagra humeralis Bosc, Journ. Hist. Nat., vol. 2, 1792, p. 179, pi. 34, 

 fig. 4. (Cayenne.) 



Decidedly brown above, with well-defined black streaks. 



Specimens seen from Venezuela (Maripa, Rio Caura; Suajwre) ; 

 British Guiana; Surinam (District of Para); Brazil (Santarem, 

 Para; Ceara; Bahia; Chapada and Arapua, Matto Grosso) ; Bolivia 

 (Buenavista, Prov. del Lara; Santa Cruz de la Sierra; Rio San 

 Julian and Rio Quiser, Chiquitos) ; and Paraguay (Puerto Pinasco 

 and Sapucay). 



Specimens from Bahia seem closely similar to those from British 

 and Dutch Guiana, here assumed to be typical since no birds from 

 Cayenne are available, so that manimhe Lichtenstein (1823) for the 

 present at least is considered a synonym of humeralis. Three speci- 

 mens from Santarem on the Amazons are very gray above, with the 

 black streaks considerably reduced. Mrs. E. M. B. Naumburg in- 

 forms me that she has seen gray birds from the Islands of Marajos. 



