396 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Bill about half as long as head, very narrow, its width at frontal 

 antia" equal to less than two-thirds the distance from nostril to tip of 

 maxilla, but decidedly greater than its depth at same point; exposed 

 culmen much shorter than middle toe without claw, distincth^ and 

 rather sharply ridged, straight to near tip, where gradually but not 

 strongly decurved, the tip of maxilla not strongly uncinate; gonys 

 decidedly longer than mandilndar rami, nearly straight, ascending 

 terminally, its base usually rather jjrominent; maxillary tomium 

 nearly straight, but more or less concave subbasally, distinctly 

 notched subterminally. Nostril longitudinally oval or sometimes 

 almost linear, with distinct, sometimes broad, superior membrane. 

 Rictal bristles well developed, and feathers of chin and frontal antise 

 with distinct bristly points. Wing moderate, much rounded, with 

 longest primaries exceeding secondaries by about length of exposed 

 ci.ilmen; seventh and eighth, or seventh, eighth, and ninth, ])rimaries 

 longest, the tenth (outermost) equal to first, sometimes longer than 

 fourth. Tail not shorter than distance from bend of wing to end of 

 secondaries, sometimes long as wing, slightly rounded or double- 

 rounded, the rectrices rather broad, at least terminally. Tarsus 

 rather long and slender, nearly one-third to slightly more than one- 

 third as long as wing, its scutellation typically exaspidean; middle 

 toe, without claw, slightly less to decidedly more than half as long as 

 tarsus, its basal phalanx united for only about half its length, or a 

 little more, to outer toe, mostly free from inner toe; outer toe, with- 

 out claw, reaching to or beyond middle of subterminal ])halanx of 

 middle toe, the inner toe decidedly shorter; hallux about as long as 

 inner toe, but much stouter, its claw as long, or nearly as long, as 

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



Coloration. — Above plain gray, the pileum, wings, and tail some- 

 times black or dusky, the crown with a partially concealed patch of 

 white ; under parts light gray, or very pale gray anteriorly and pale 

 yellow posteriorly. 



Nidification. — Nest cup-shaped, placed in a bush or beneath an 

 overhanging bank, composed of various soft materials lined with 

 plant down, feathers, etc. Eggs (2-4) white or cream-colored, with or 

 without black and grayish spots around larger end. 



Range. — Costa Rica to Peru, Argentina, Paraguay, and Uruguay. 

 (About ten species and subspecies.) 



I without hesitation remove from this genus Tyrannula parviro- 

 stris "• Gould, type of the genus ColorJiampJius Sundevall,^ which differs 



n Tyrannula parvirostris Gould, ZooL Voy. "Beagle," iii, 1841, 48 (Santa Cruz, Pata- 

 gonia; type now in coll. Brit. Mus.). — Myiobius parvirostris Gray, Zool. Voy. "Bea- 

 gle," iii, 1841, 48. — Serphophaga parvirostris Sclater, Cat. Am. Birds, 1862, 212; Cat. 

 Birds Brit. Mus., xiv, 1888, 105. 



i Colorliamphus Sundevall, Met. Nat. Av. Disp. Tent., 1872, 59. (Type, Tyramiula 

 parvirostris Gould.) 



