ON SOME -NEW FORMS OF AMERICAN BIRDS. 617 
This race has a considerable resemblance to var. estivalis, but 
differs in some appreciable points. The brown of the upper parts 
is paler, and the ashy edging to the feathers appears rather less 
extensive. The dark brown blotches on the back are of greater 
extent, the black streaks on the back confined to a mere streak 
along the shaft. There is less of an olive tinge across the breast. 
The proportions of the present race differ more from those of 
estivalis than do the colors, the bill being more slender, and the 
wings and tail considerably longer. 
The resemblance to P. Botterii (=estivalis, var. Botterii) of 
Sclater, from middle Mexico (Orizaba, Colima, ete.), is very 
close; the difference being greater in the proportions than in the 
colors, the latter having a shorter wing and tail, with thicker bill, 
as in var. estivalis. In Botterii there is rather a predominance of 
the black over the rufous in the streaks above. 
In the “ Birds of North America,” the specimen described above 
was referred to P. Cassini, those specimens upon which the latter 
species was founded being considered as in quite immature plu- 
mage. A more recent examination of additional material, how- 
ever, has compelled us to regard them as representing a perfectly 
distinct species. In consequence of the similarity of the specimen 
in question to estivalis, as noted in the article referred to above, 
the general acceptation of the name Cassini, has been that of a 
term designating a variety of the common species; but we find it 
necessary to retain under the head of “ Cassini” only the typical 
Specimens from the-Rio Grande region, and refer the supposed aber- 
rant specimen to estivalis. In this Los Nogales specimen we find 
existing such differences in proportions and colors as are sufficient 
to warrant our bestowing upon it a new name, and establishing it 
as the middle province race of estivalis, in this way connecting the 
South Atlantic and Mexican races (var. æstivalis and var. Botterii) 
by a more similar form than the P. Cassini, which must be set 
apart as an independent form,—in all probability a good species. 
Several facts are favorable to this view. First, we have, of the 
P. Cassini, specimens which are beyond question in perfect adult 
Plumage, and others which are undoubtedly immature ; they differ 
from each other only in such respects as would be expected, and 
agree substantially in other characters, by which they are distin- 
guished from the different plumages of estivalis. Secondly, the 
region to be filled by a peculiar race of æstivalis is represented by 
