BIRDS—LANIIDAE-—YIREO. 
329 
Sub-Family VIREONINAE. 
The characters of the Vireoninae, as already given, will serve to distinguish them from the 
other North American Laniidae. The bill, though slenderer and more cylindrical, has the 
same abrupt and lengthened hook at the tip. 
The association of Icteria with Vireo, as made by most ornithologists, appears to me highly 
unnatural, its place being more appropriately among the Sylvicolidae. 
VIRFO, Tie ill. 
Vireo, Vieill. Ois. Am. Sept. I, 1807, 83. Type Muscicapa novcboracensis, Gm. 
Ch.— Bill short, strong, straight; the culmen slightly curved ; the sides much compressed to the tip, which is rapidly curved 
and deflected ; the gonys long and ascending ; the gape with short weak bristles ; the nostrils basal, rounded, and exposed, the 
feathers of the head advancing forward on the bill to the nostril. Wings variable, rather long, and pointed; the first quill 
sometimes spurious, the larger outer one always graduated a little. Tail nearly even, and rather short. Tarsi longer than the 
middle toe. Outer toe a little longer than the inner ; hind toe rather shorter than the middle one. 
I bave found it very difficult to arrange the North American Vireos satisfactorily by dividing 
into Vireo and Vireosylvia , according as there is a spurious first primary or none. This char¬ 
acter, though strongly marked, combines species which otherwise appear quite dissimilar, and 
separates some which seem very closely related. Thus Vireo gilvus and philadelphicus are in 
some stages of plumage hardly to be distinguished, except by the spurious primary of the 
former ; while the V. Jlavifrons , without this spurious primary, is in other essentials very near 
noveboracensis and solitarius, which possess it. 
In the difficulty of establishing any trenchant lines of distinction, I have concluded to con¬ 
sider all the species as Vireo, and to divide them into the following sections : 
Vireosylvia. —Bill long, rather slender, light horn color. Wings long ; no spurious pri¬ 
mary. Body slender. Top of the head plumbeous, very different from the back, bordered by 
a line of black. • 
V. olivaceus, flavoviridis, altiloquus, virescens. Type V. olivaceus. 
Vireo. —Bill shorter, rather slender, light horn color, (except in atricapillus.) Wings 
shorter. First primary spurious, except in philadelphicus. Body slender. Top of the head 
scarcely different from the back, (except in atricapillus.) 
V. philadelphicus, gilvus, belli, atricapillus. Type V. gilvus. 
Lanivireo. —Bill rather stout and short, dark plumbeous in color. Wings moderate. Body 
stout. First primary spurious, except in jlavifrons. 
V. noveboracensis, huttonii, solitarius, cassini, Jlavifrons. Type V. Jlavifrons. 
The following synopsis, though its arrangement is not perfectly natural, may yet aid in a 
ready identification of the species : 
A. NO SPURIOUS QUILL. 
Crown ash colored, very different from the neck, bordered on each side by a dusky line within 
a white superciliary one. No black line on the side of the throat, except in altiloquus. 
Nearly pure white beneath ; the under tail coverts with the faintest tinge of sulphur. 
First and fourth quills nearly equal. V. olivaceus. 
Sides greenish yellow; under tail coverts bright gamboge yellow. First quill longer 
than the fifth and sixth. V. flavoviridis. 
42 b 
