360 REVIEW OF AMERICAN BIRDS. [PART I. 
Vireo pusillus. 
Vireo pusillus, Cougs, Pr. A. N. Sc. Phila. 1866. 
? Vireo bellii, Cooper, Pr. Cal. Acad. 1861, 122 (Fort Mohave). 
fab. Cape St. Lucas, San Diego, Fort Mohave, and Arizona. 
Somewhat similar in general appearance to Vireosylvia gilva and swainsoni, 
but smaller. Bill very small; tarsi lengthened. Wings about equal to the 
tail, which is lengthened, graduated, and with the feathers narrow and pointed. 
Exposed part of Ist primary about half that of the 2d, which is intermediate 
between 7th and 8th; the 4th and 5th longest. 
Above grayish-ash, with a tinge ef olive behind. Beneath, including the 
inside of the wings, white, with a soiled tinge on the sides of the throat and 
across the breast. Ax- 
illars and flanks, ex- 
hibiting a faint trace of 
greenish-yellow. Eye- 
lids and a short line 
from the nostrils to the 
eye whitish; no other 
stripe apparent. A 
dusky loral spot. Pri- 
mary coverts edged in- 
distinctly with whitish, producing an obscure band (a second on the middle 
coverts hardly appreciable). Quills and tail feather edged externally 
with pale grayish-olive, the innermost secondaries with whitish. Bill dusky 
above, whitish beneath. Legs plumbeous. Iris of two specimens marked as 
“light brown,” of another as “rufous.” 
The details of structure taken from No. 23,785, of color from 23,788. Length 
of 23,785, 4, 4.80 when fresh, of skin, 4.25 ; wing, 2.25 ; tail, 2.25 ; bill above, 
.o7; tarsus, 73; middle toe and claw, .50; hind toe and claw, .42. First 
quill, .70; 2d, 1.40; longest (5th), 1.64. (Cape St. Lucas.) 
Vireo pusillus, Cotes, (California.) 
4 
Since writing the preceding description, I have received a Vireo 
(No. 81,895), collected by Dr. Cooper, at San Diego, which, al- 
though considerably larger, I cannot distinguish specifically. The 
difference in size is what might be expected between specimens from 
Cape St. Lucas and San Diego, and the occurrence of a Cape species 
at the latter place is in accordance with the facts observed in other 
instances where such birds as Sialia arctica, Polioptila melanura, 
etc., equally peculiar to the middle province, have found their way to 
the California coast at San Diego, through the break in the coast 
range of mountains. 
The larger specimen somewhat resembles V. pallens of Central 
America, but has a much smaller bill and a longer tail, with but one 
distinct white band on the wing. ‘The bill is about the size of that 
in V. hultoni; but the white under parts and other differences of 
