Family VIREONIDÆ.
THE VIREOS.
Small[1] dentirostral acutiplantar Oscines with the tarsus longer than middle toe and claw, the acrotarsium distinctly scutellate; hallux (without claw) as long as or longer than inner toe (without claw), the latter decidedly shorter than outer toe; basal phalanx of middle toe completely adherent to both outer and inner toe; tenth primary very short (little if any more than half as long as eighth), sometimes rudimentary and concealed (the wing then being typically "nine-primaried"); the wing always longer than the tail, and the plumage never streaked, barred nor spotted, even in young.
Bill very variable as to relative size but never longer than head (usually very much shorter, often less than half as long); also very variable as to relative length, depth, and breadth; culmen strongly curved terminally, sometimes nearly straight for basal half or more, the tip of maxilla more or less distinctly uncinate; maxillary tomium nearly straight, distinctly notched subterminally; mandibular tomium also sometimes with a subterminal notch, the tip of the mandible produced into an acute ascending point; gonys decidedly longer than unfeathered portion of mandibular rami (nearly or sometimes quite equal to length of maxilla from nostril), more or less strongly convex. Nostril at least partly exposed, longitudinally oval or ovate (sometimes roundish) in lower anterior portion of nasal fossæ, overhung by a distinct membraneous operculum. Rictal bristles inconspicuous, only two on each side well developed; the feathers of the frontal antiæ, however, with well-developed, sometimes conspicuous, bristle-like tips, these sometimes reaching beyond and partially covering nostrils. Wing variable but always longer than tail, and always with the tenth (often also the ninth) primary much reduced in length; tenth primary never much more than half as long as ninth, usually much less, sometimes rudimentary and concealed; ninth primary never longer than seventh. Tail shorter (usually much shorter) than wing even, slightly rounded, double-rounded, or emarginate, the rectrices rather narrow. Tarsus longer than middle toe with claw, the acrotarsium distinctly scutellate but pianta tarsi undivided; lateral toes unequal, the outer decidedly longer than the inner; hallux (without claw) equal to or longer than inner toe (without claw); basal phalanx of anterior toes abbreviated, that of the middle toe shorter than that of the inner or the two basal phalanges of the outer toe, and adherent to both lateral toes for its entire length.
Coloration. — Very variable, but never streaked, spotted, nor barred;
plain olive, whitish, huffy or yellowish hues prevailing, sometimes
- ↑ The wing not more than 75 mm., usually much less.
