338 » REVIEW OF AMERICAN BIRDS. [PART I. 
In a pretty extensive series of specimens of South American 
Vireos, which have been referred to V. chivi, agilis, bartramit, ete. 
of authors, supposed to be synonyms of the same species, I find 
considerable differences which apparently indicate the presence of 
two or even three species, differing almost too much in size and 
coloration to be considered the same. I have therefore selected the 
specimens from Captain Page’s Paraguay expedition as typical of 
the oldest name, V. chivi, based on Azara’s descriptions. These 
specimens, two in number, agree with Azara’s bird in the small size ; 
the coloration is less intense than in the rest, the yellow of the under 
parts being not much brighter than in olivaceus, but as a spring 
plumage this is to be expected, if, as is probable, Azara’s descrip- 
tion was taken from autumnal birds. 
The great inferiority in size to V. olivaceus, and the difference in 
the wing formula, will at once distinguish this species or race. The 
coloration of No. 16,340 is almost precisely that of No. 1,418, the 
type of the description of V. olivaceus, the olive being only a little 
deeper, the axillars brighter yellow. 
If there are two species of South American Vireos of the chivi 
type, as suggested, the more southern appears to be the smaller 
and the northern one the larger, although not closely restricted. 
Thus a specimen in the collection labelled ‘‘ Buenos Ayres,” possibly 
erroneously, however, is as large as the largest, while two from 
Bahia are as small as the La Plata skins described. 
Smith-|Collec-|} Sex 
sonian| tor’s | and Locality. C Wien Received from Collected by 
No. No. | Age. S eo 
10,173? ue ye Bahia, Brazil. erste Dr: iGeyGabanig. e)) tal Seen 
ss 158 ds ee one Gab. Lawrente. i) mer seers 
16,340 | 115 ie) Brazil. Oct. 1859. | Capt. Page, Expl. Chr. Wood. 
20,973 37 J Vermejo River. Feb. 1860. “* fof Parana. “ 
Vireosylvia agilis. 
Lanius agilis, Licur. Verz. Doubl. 1823, no. 526 (Bahia, Brazil).— 
?Thamnophilus agilis, Sprx, Av. Bras. I, tab. xxxiv, fig. 1.—Phyllo- 
manes agilis, Burm. Th. Bras. Végel, II, 1856, 108.— Vireosylvia 
agilis, Scuater, P. Z. S. 1860, 64, 273 (Ecuador).—Is. Catal. 1861, 
44, no. 263 (Bogota, etc.). 
Vireo bartramii, Swainson, F. B. A. I, 1831, 235 (not of Aup.). 
Vireosylvia virescens, Cassin, Pr. A. N. Sc. 1851, 151.—Scrarer, P. Z. 8. 
1855, 151 (Bogota).—Vireo virescens, Barrp, Birds N. Am. 1858, 
333 (Brazil), not of VrIerLL. 
Hab. South America; south to Buenos Ayres, Ecuador, Guatemala. 
