Bulletin - United States National Museum - si-pddr - Smithsonian ...

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 juvenal 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 Sapucay).
and Paraguay (Puerto Pinasco
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 specimens
from Santarem on the Amazons are very gray above, with the
black streaks considerably reduced. Mrs. E. M. B. Naumburg informs
me that she has seen gray birds from the Islands of Marajos.
: