_Icteria_, VIEILLOT, Ois. Am. Sept. I, 1807, iii and 85. (Type,
MUSCICAPA VIRIDIS, GM. _Turdus virens_, LINN.)
[Line drawing: _Icteria virens._
2260]
GEN. CHAR. Bill broad at base, but contracting rapidly and becoming
attenuated when viewed from above; high at the base (higher than broad
opposite the nostrils); the culmen and commissure much curved from
base; the gonys straight. Upper jaw deeper than the lower; bill
without notch or rictal bristles. Nostrils circular, edged above with
membrane, the feathers close to their borders. Wings shorter than
tail, considerably rounded; first quill rather shorter than the sixth.
Tail moderately graduated; the feathers rounded, but narrow. Middle
toe without claw about two thirds the length of tarsus, which has the
scutellæ fused externally in part into one plate.
The precise systematic position of the genus _Icteria_ is a matter of
much contrariety of opinion among ornithologists; but we have little
hesitation in including it among the _Sylvicolidæ_. It has been most
frequently assigned to the _Vireonidæ_, but differs essentially in the
deeply cleft inner toe (not half united as in _Vireo_), the partially
booted tarsi, the lengthened middle toe, the slightly curved claws,
the entire absence of notch or hook in the bill, and the short,
rounded wing with only nine primaries. The wing of _Vireo_, when much
rounded, has ten primaries,—nine only being met with when the wing is
very long and pointed.
Of this genus only one species is known, although two races are
recognized by naturalists, differing in the length of the tail.
I. virens. Above olive-green; beneath gamboge-yellow for the
anterior half, and white for the posterior. A white stripe over the
eye.
Length of tail, 3.30 inches. _Hab._ Eastern United States to
the Plains; in winter through Eastern Mexico to Guatemala …
var. _virens_.
Length of tail, 3.70 inches. _Hab._ Western United States
from the Plains to the Pacific; Western Mexico in winter …
var. _longicauda_.
Icteria virens, BAIRD.