386 . BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



l()no;or than iiiiddlc toe with claw, coloration plain olive-green (paler 

 and sometimes streaked below), the adult males with edge of outer 

 web of outermost prhnary rough (the barbs stiffened and at right 

 angles with shaft). 



Bill shorter than head, very broad, its width at frontal antia^ equal 

 to or exceedmg distance from nostril to tip of maxilla and at least 

 twice its depth at same point, broadly triangular in vertical profile, 

 with lateral outlines more or less convex subtermmally; exposed 

 culmen decidedly, to much, shorter than tarsus, distinctly to obtusely 

 ridged, straight basally, then more and more strongly decurved 

 terminalh^, the tip of maxilla distinctly uncinate; gonys about as 

 long as mandibular rami, the inter-ramal space broadly rounded 

 anteriorly; maxillary tomium faintly sinuated or nearly straight, 

 distinctly notched subterminally. Nostril rather small, roundish, or 

 subvertically broadly oval, in anterior end of nasal fossae, with visible 

 membrane behmd but not above. Rictal bristles strong and feathers 

 of chin and frontal antia' with well developed bristly points. Wing 

 moderate, rather pointed, but longest primaries exceeding secondaries 

 by much less than length of tarsus (sometimes by less than length of 

 exposed culmen) ; seventh and eighth primaries longest, the sixth and 

 ninth but little shorter, the tenth (outermost) about equal to fifth, 

 sometimes slightly exceeding sixth, the barbs of its outer web at right 

 angles with the shaft, stiffened, and with strongly recurved tips." 

 Tail as long as wing from bend to end of secondaries, or slightly 

 shorter, even or very slightly rounded or double-rounded, the rectrices 

 widening terminally. Tarsus rather short and stout (one-fourth as 

 long as wing or a little less), its scutellation typically exaspidean, with 

 divisions of acrotarsium sometimes indistinct on outer side; middle 

 toe with claw decidedly shorter than tarsus, united to outer toe for 

 the whole of its first and a small part of its second phalanx, to inner 

 toe for greater part of its basal phalanx; outer toe, without claw, 

 reacliing nearly to terminal joint of middle toe, the inner much 

 shorter, barely extending to middle of subterminal phalanx of middle 

 toe; hallux about as long as inner toe, its claw" decidedl}" shorter than 

 the digit; all the claws moderately curved, sharp, much compressed. 



Coloration. — Above plain olive-green; beneath light olive-green, 

 or pale olive, streaked with pale yellowish, anteriorly, the tln"oat 

 sometimes grayish, pale yellow posteriorly; one species with throat 

 and chest fulvous. 



Nidification. — (Unknown ?) 



Range. — Southern Mexico to Ecuador and southeastern Brazil. 

 (Four species.) 



a The result being that when the finger is drawn along the edge from base to tip the 

 strongly rorurved and stiffened barbs resist the movement, exactly as in the Hirundine 

 genus Stelgidopteryx. 



