BIRDS OF NORTH AND MIDDLE AMERICA. 35 



near base, more strongly decurved terminally, the tip of mandible 

 distinctly but not strongly uncinate; maxillary tomium faintly con- 

 cave, distinctly notched sub terminally; 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 setse to feathers of chin. Wing moderate, 

 with longest primaries projecting slightly but decidedly beyond 

 secondaries; fifth and sixth ]>rimaries 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) moderatel}^ 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. Plum- 

 age full, lax, and blended, that of the rump elongated, fluffy; featliers 

 of crown and occiput (especially the latter) elongated, distinctly 

 outUned, forming a distinct but not conspicuous decumbent crest. 



Coloration. — Adult males mth under parts (usually the upper 

 also) conspicuously barred with black and white, or else (in T. 

 virgatus) dull slate-gray, streaked with whitish; adidt females and 

 young tawny or rufescent above, ochraceous or bufTy 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 OF THAMNOPHILUS.a 



a. Plumage wholly black and white, in transverse bars. 



6. Pileum wholly black. (Eastern Panamd, including San Miguel Island, and 

 Caribbean coast of Colombia.) 



Thamnophilus radiatus nigricristatus, adult male (p. 37). 



a Owing principally to lark of sufficient material thivS key is confined mainly to the 

 forms belonging properly to the present work and is by no means as satisfactory as ia 

 desirable. 



