BIRDS OF NORTH AND MIDDLE AMERICA. 127 



(at least posteriorly) by an extension of the membraneous integu- 

 ment of the nasal fossae, an internal tubercle or facet visil^le within 

 the posterior portion. Rictal bristles present, but inconspicuous; 

 feathers of chin, malar antiae, and loral region with distinct terminal 

 setfB. Wing moderate or rather large, with longest primaries extend- 

 ing decidedly beyond secondaries; sixth and seventh, or seventh, 

 primaries longest, the tenth (outermost) three-fifths as long as the 

 longest, or slightly more, the ninth equal to or slightly longer than 

 secondaries. Tail slightly more than one-half to three-fifths as long 

 as wing, slightly rounded, the rectrices (12) rather broad, rounded 

 terminally. Tarsus nnich longer than whole culmen, a little less than 

 two-fifths as long as wing, the acrotarsium indistinctly scutellate 

 (scutella sometimes obsolete except on lower portion), the planta 

 fused, at least for greater part; middle toe, with claw, much shorter 

 than tarsus; outer toe, without claw, reaching to about middle of 

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

 hallux equal to or slightly longer than inner toe; basal phalanx of 

 middle toe wholly united, the second phalanx partl}^ united, to outer 

 toe (the adhesion involving the first two phalanges of outer toe), 

 united for half its length or more to inner toe; claws rather large, 

 moderately curved, extremely compressed, that of the hallux shorter 

 than the digit (but sometimes nearly as long). Plumage full, soft, 

 and blended, that of rump and flanks more elongated and lax; 

 feathers of pileum not elongated. 



Coloration. — Adult males gray and black above, the back with 

 white spots or lunulate bars, the wing-coverts, tertials, and tail 

 tipped with white; or back rufous or chestnut, with a concealed patch 

 of white, the wing-coverts, tertials, and tail tipped with cinnamon- 

 rufous; throat black, rest of under parts white, passing into gray or 

 buff}' on flanks, the chest spotted with black, or whole under parts 

 plain gray. Adult females somewhat like males, but browner above 

 with markings fulvous or buffy instead of white, the throat whitish, 

 and black markings of chest replaced by brownish, or (in slate- 

 colored species) head and under parts rufescent or the general color 

 of under parts gray, with white throat and dusky flanks.'^ 



Range. — Costa Rica to western Ecuador, Amazon Valley, and 

 Guiana. (Six species. ?)* 



o- On account of insufficiency of material, I am not able to give the full range of color 

 variation in this group. 



& Of the species referred to the genus Uypocnemis by Dr. Sclater and other recent 

 authors I have seen in this connection only H. cantator (type of the genus), H. poedlo- 

 nota (Cuvier), H. Icpidonoia Sclater and Salvin, II. leucophrys (Tschudi), H. myio- 

 therina (Spix), //. luguhris (Cabanis and Heine), //. nsevia (Gmelin), and U. naevioides 

 (Lafresnaye). The second, third, seventh, and eighth of these I have removed from 

 Uypocnemis on account of the very different amount of adhesion of the anterior toes 



