728 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



rami, slightly convex; maxillary tomium nearly straight or gently 

 concave anteriorly, distinctly notched subterminally. Nostril mostly 

 exposed, rather large, longitudinally oval or elliptical, overhung by dis- 

 tinct membraneous operculum. Rictal bristles distinct. Wing short, 

 rounded, very concave beneath, with longest primaries exceeding 

 secondaries by less than length of exposed culmen ; adult males with 

 four or five outermost primaries narrow, much bowed, rather rigid, the 

 fourth to ninth, inclusive, usually longest and nearly equal in length, 

 the tenth usually equal to third (in one species « the sixth to ninth 

 longest, and tenth equal to or longer than fifth). Tail more than 

 half (but less than two-thirds) as long as wing, even or very slightly 

 double-rounded, rounded, or emarginate, the rectrices rather narrow, 

 with rounded tij). Tarsus long (more than two-thirds as long as tail), 

 stout, its scutellation typically exaspidean, but acrotarsium fused or 

 with scutella obsolete, at least on upper half of outer side; heel joint 

 bare, except on sides and front of tibial portion; middle toe, with claw, 

 much shorter than tarsus, its second phalanx adherent to outer toe for 

 at least two-thirds its length, the first united for at least half its length 

 to inner toe; outer toe, without claw, reaching to beyond middle of 

 subterminal phalanx of middle toe, the inner decidedly shorter; hal- 

 lux (without claw) about as long as inner toe but stouter; claws rather 

 long and sharp, moderately curved. 



Plumage and coloration. — Contour feathers rather long, completely 

 blended; head normally feathered, but feathers of chin and throat 

 elongated (especially in males, in which forming a conspicuous erectile 

 tuft). Adult males with pileum, back, scajnilars, and wings black, 

 rum]) olive-green or gray, broad collar across hindneck, together with 

 auricular region, chin, throat, and chest white, yellow, or orange, 

 underparts of body ])ale gray, light olive-green, olivaceous-orange, or 

 lemon yellow;'' adult females plain olive-green above, paler and more 

 yellowish below. 



Nidification. — Nest shallow cup-shaped, suspended to a forked twig 

 of a bush or small tree, very thin, composed of long grass-stems and 

 l)lant-fibers. Eggs whitish or buffy, longitudinally streaked or 

 ])lotched with reddish brown, etc., the markings sometimes confluent 

 in a ring round larger end. 



Range. — Southern Mexico to Peru and southeastern Brazil. (About 

 ten species and subspecies.) 



fl In M. aurantiacus. 



b M. coronatus {Chiromachseris coronata Boucard), which I have not seen, differs 

 materially in its pattern of coloration from the other members of the genus, which are 

 remarkably alike in this respect. It has, in the adult male (the female being unknown) 

 the upper parts black, interrupted by a nuchal collar of bright yellow, which t xtends 

 over sides of head, the throat l)lack, the remaining underparts gray. Possibly it may 

 not belong to this genus. 



