66 BULKETIN 50, UNITED STATES NATIONAL MUSEUM. 



Small Formicariidae resembling Myrmothenda but differing in 

 relatively much longer tail (much more tlian half to more than two- 

 thirds as long as wing), much stouter and relatively shorter and less 

 depressed bill, the adult males neither streaked nor plain gray or 

 slaty. 



Bill decidedly shorter than head, rather stout, not depressed 

 basally, its width at frontal antise about equal to or very little greater 

 than its depth at same ]:)oint and equal to less to slightly more than 

 half the distance from nostril to tip of maxilla; culmen distinctly 

 and rather sharply ridged, straight or nearly so for most of its length, 

 rather strongly and abruptly decurved terminally, the tip of maxilla 

 minutely but distinctly uncinate; tomium nearly straight, that of 

 maxilla distinctly, that of mandible slightly notched subterminally; 

 gonys faintl}^ convex (more decidedly so basally). Nostril exposed, 

 posteriorly nearly (sometimes quite) in contact wdth feathering of 

 latero-frontal antise, roundish or broadly oval, margined for basal 

 half by the membraneous cover of nasal fossae (this sometimes extend- 

 ing along upper margin as a narrow "operculum"), and with a con- 

 spicuous internal tubercle. Rictal bristles present but minute 

 (practically obsolete); feathers of chin, malar antioe, and lores with 

 slender terminal setse. Wing moderate, with longest primaries dis- 

 tinctly longer than secondaries; sixth and seventh, or fifth, sixth, 

 and seventh, primaries longest, the tenth (outermost) slightly more 

 than one-half to nearly two-thirds as long as the longest, the ninth 

 about as long as secondaries or a little shorter. Tail much more 

 than half to more than two-thirds as long as wing, much rounded, 

 the rectrices (12) moderately broad to rather narrow^, rounded ter- 

 minally. Tarsus decidedly longer than exposed culmen, less than 

 one-third as long as wing (except in M. ormata), the acrotarsium 

 distinctly scutellate, the planta tarsi usually fused (at least in part) 

 or with the scutella somewhat indefinite as to form and arrangement 

 (with a general tendency toward two longitudinal series); middle 

 toe, with claw, decidedly shorter than tarsus; outer toe, without 

 claw, reaching to beyond middle of subterminal phalanx of middle 

 toe, the inner toe slightly shorter; hallux about as long as inner toe 

 but much stouter; basal phalanx of middle toe Avholly united to 

 outer toe, for about half its length to inner toe; claws moderate in 

 size and curvature, that of the hallux decidedly shorter than the 

 digit. Plumage soft, lax, and bleudetl, that of rumj) and flanks 

 much elongated and fluffy; feathers of pileum not elongated. 



Coloration."^ — Adult males plain gray or slate color above, the 

 wings black, spotted witli wldte, the tail black with white tip to 



« Not having been able to examine much the greater number of the; species referred 

 by Dr. Sclater to Myrmothenda (see note on page 62) I am not able to define the 

 full range of variation as to coloration in this group. 



