59. 
330 SYSTEMATIC SYNOPSIS. — PASSERES — OSCINES. 
which the lst is short (one-half to one-fourth the second), or spurious, or apparently wanting 
(being rudimentary and displaced). Size small, er 7 inches; coloration simple, mostly and 
oftenest greenish ; young not spotted or streaked. 
This family was formerly united with the next (Laniide), chiefly on account of the 
resemblance in the shape of the bill of certain species to that of the shrikes ; but the likeness 
is never perfect, and there are other more important characters, especially in the structure of 
the feet, by which the two groups may be discriminated. The Vireonide are peculiar to 
America; they are a small family of five or six genera and nearly seventy recorded species, 
of which about five-sixths appear to be genuine. The typical and principal genus, Vireo, con- 
taining nearly thirty species, is especially characteristic of North America, though several species 
oecur in the West Indies and Ceutral America; one genus and species, Laletes osburni, is 
exclusively West Indian; the rest — Cyclarhis, Hylophilus, Vireolanius, and Neochloe — are, 
with one exception, South and Central American. In further illustration of the characters of 
the group, I offer some remarks under the head of the only genus with which we have to do in 
the present connection. 
VIR/EO. (Lat. vireo, am green or flourishing.) GREENLETS. Bill like that of a shrike 
in miniature, moderately or very stout, shorter than the head, compressed at least toward the 
end, distinctly hooked and notched at the tip, sometimes with trace of a tooth behind the notch 
of the upper mandible, and usually a nick in the under mandible too. Rictal bristles con- 
spicuous, and others present among the frontal and mental feathers. Nasal fossee nearly filled 
with short erect feathers. Toes extensively coherent at base, as explained under head of the 
family ; lateral toes of unequal lengths; claws stout, narrowly compressed, much curved and 
acute. Wings at least as long as the tail, more or less rounded ; sometimes much longer and 
quite pointed ; of 10 primaries, the 1st usually evident, though short and spurious, but some- 
times (in the section Vireosylvia and in Vireo flavifrons) rudimentary aud more or less com- 
pletely concealed (exceptionally obvious even in these species). Tail short, even, of narrow 
feathers. Size small; length usually five or six inches. Coloration simple; above olivaceous 
or grayish, the crown like the back, or ashy (in one case brown, in another black), the under 
parts white, or white and yellow, or partly olivaceous. Sexes quite indistinguishable ; young 
similar, not spotted or streaked. Migratory in N. Am. Insectivorous, arboricole. Nest pen- 
dulous ; eggs white, spotted. 
The numerous species of this genus have been divided into several groups, but no violence 
will be done by considering them all as Vireo—in fact, it is difficult to do otherwise. For 
even the seemingly substantial division into two genera, according as there is an evident 
spurious Ist primary or apparently none, separates species, like gilvus and philadelphicus, 
hardly otherwise specifically distinguishable; while another division into two genera, according 
to the shape of the wings and length of the spurious Ist primary or its absence, is subject to 
some uncertainty of determination, and unites species, like olivaceus and flavifrons, most dis- 
similar in other respects. The fact is, that almost every single species of Vireo has its own 
peculiar form, in shape of bill, proportions of primaries, ete., and these details cannot well be 
considered as of more than specific value. These slight differences are perfectly tangible and 
surprisingly constant, rendering the determination of the species comparatively easy, though 
these birds bear to each other a close general resemblance in size and color. They are all more 
or less olivaceous above, sometimes inclining to gray or plunbeous, with the crown either like 
the back, or else ashy, —in one species, however, brown, and in another black ; and white or 
whitish below, usually more or less tinged with yellow. The coloration is very constant, the 
sexes being indistinguishable, and the young differing little, if at all, from the adults. All are 
small birds, —about 5 or 6 inches long. Asa group the student will probably have no diffi- 
culty in recognizing them by the foregoing diagnosis, as the character of the feet seems to be 
peculiar, among N. Am. birds, and is at any rate diagnostic when taken in connection with the 
a a 
