near base, more strongly decurved terminally, the tip of mandible distinctly but not strongly uncinate; maxillary tomium faintly concave, distinctly notched subterminally ; mandibular tomium nearly straight, minutely but distinctly notched and toothed subterminally, the tip of mandible acute, recurved; gonys moderately convex, ascending terminally, rather prominent basally. Nostril exposed, broadly longitudinally oval, with the internal tubercle barely visible in upper posterior portion. Rictal bristles present but very small, shorter than the terminal setæ to feathers of chin. Wing moderate, with longest primaries projecting slightly but decidedly beyond secondaries; fifth and sixth primaries longest, the seventh but little shorter; tenth (outermost) about three-fifths as long as longest, the ninth shorter than secondaries. Tail about as long as wing (at least five-sixths as long), much rounded (graduation equal to or exceeding length of exposed culmen), the retrices (12) moderately broad, rounded terminally. Tarsus equal to or longer than commissure, about one-third as long as wing, distinctly scutellate, the plantar scutella in two longitudinal series, elongate-quadrate or lozenge shaped; middle toe, with claw, much shorter than tarsus (toe alone shorter than exposed culmen); outer toe, without claw, reaching to or a little beyond middle of subterminal phalanx of middle toe, the inner toe a little shorter; hallux about as long as inner toe, but much stouter; basal phalanx of middle toe wholly united to outer toe, united to inner toe for about half its length; claws moderate in size and curvature, that of the hallux much shorter than its digit. Plumage full, lax, and blended, that of the rump elongated, fluffy; feathers of crown and occiput (especially the latter) elongated, distinctly outlined, forming a distinct but not conspicuous decumbent crest.
Coloration. — Adult males with under parts (usually the upper also) conspicuously barred with black and white, or else (in T. virgatus) dull slate-gray, streaked with whitish; adult females and young tawny or rufescent above, ochraceous or buffy below.
Nidification. — Nest pensile, suspended from a fork like that of a Vireo. Eggs white or creamy white, marked with brownish spots or streaks.
Range. — Southern Mexico to Cayenne, Paraguay, Bolivia, and Peru. (About ten species, not including subspecies.)
KEY TO THE SPECIES AND SUBSPECIES OP THAMNOPHILUS.[1]
a. Plumage wholly black and white, in transverse bars.
- b. Pileum wholly black. (Eastern Panamá, including San Miguél Island, and Caribbean coast of Colombia.)
Thamnophilus radiatus nigricristatus, adult male (p. 37).
- ↑ Owing principally to lack of sufficient material this key is confined mainly to the forms belonging properly to the present work and is by no means as satisfactory as is desirable.
