400 . BULLETIN 50^ UNITED STATES NATIONAL MUSEUM. 



longer than head ; short, very much rounded wing (less than two and 

 a half tunes as long as culmen, from base), and very plain coloration, 

 the upper surface plain brown (sometimes rufescent on pileum), the 

 under parts plain ochraceous, sometimes passing into white on abdo- 

 men and under tail-covertS. 



Bill as long as or slightly longer than head, narrow, slightly com- 

 pressed, very slightly decurved terminally, its depth at anterior end 

 of nostrils slightly greater than its width at same point and equal to a 

 little more than one- third the distance from nostril to tip of maxilla; 

 exposed culmen about as long as combined length of tarsus and first 

 and second phalanges of outer anterior toe, straight for basal half 

 (more or less), then very gently but increasingly decurved terminally, 

 rather distinctly ridged; gonys twice as long as mandibular rami, 

 or slightly more, very faintly convex and broadly rounded basally, 

 very faintly concave and indistinctly ridged terminally; maxillary 

 tomium faintly concave for most of its length. Nostril obliquely 

 broadly oval, in anterior end of nasal fossa, completely hidden by the 

 overlying very rigid but slender, decurved, antrorse prefrontal bris- 

 tles. Rictal bristles recurved, long and very strong; antrorse 

 bristles of malar apex smaller but well developed ; feathers of chin 

 antrorse, with very long, recurved, bristly tip, these bristles, as well 

 as the prefrontal ones, with distinct lateral pinnae. Wing short 

 (scarcely three times as long as exposed culmen), much rounded, the 

 longest primaries exceeding distal secondaries by much less than 

 length of tarsus; fifth, sixth, and seventh primaries longest, the 

 eighth equal to or slightly shorter than fourth, the ninth equal to or 

 slightly shorter than first, the tenth (outermost) about half as long 

 as longest primary or slightly less. Tail about as long as wing, 

 graduated for about two-sevenths its length (about length of tarsus), 

 the rectrices rather narrow. Tarsus nearly as long as middle toe 

 with claw, slender. 



Plumage and coloration. — Plumage in general full, lax, and blended; 

 remiges and rectrices rather soft. Above plain brown, the pileum 

 sometimes rufescent, beneath ochraceous or tawny, sometimes pass- 

 ing into white on abdomen and under tail-coverts. 



Range. — Eastern Panama to northeastern Peru and central Brazdl. 

 (Five species.)" 



KEY TO THE BROWN-HEADED SPECIES OP NONNULA. 



a. Under tail-coverts and anal region white; pileum chestnut or more or lesa strongly 

 tinged with that color, the back distinctly more olivaceous. 



o The above generic description is taken from N. frontalis only, that being the only 

 species available when description was written. 



