BIRDS OF NORTH AND MIDDLE AMERICA. 341 



d. Very small forms (wing not more, usually much less, than 62 mm.), with bill 

 norrowly triangular or subspatulate, its width at frontal antise much less 

 than distance from nostril to tip of maxilla, exposed culmon longer than 

 middle toe with claw, basal phalanx of middle toe wholly united to outer 

 toe, and tail less than seven-eighths as long as wing." 

 €. Tail at least two-thirds as long as wing. 



/. Bill decui'ved, with culmen strongly arched Oncostoma (p. 357) 



Jf. Bill not decurved, the culmen nearly straight. ' 



g. Outer primaries not reduced in size, the eighth longer than first. 



h. Bill larger, the exposed culmen decidedly longer than middle toe 

 with claw. 

 i. Bill relatively larger (exposed culmen at least one-fourth as long 

 as wing), broader and less tapering (sul)spatulate) terminally; 



pilcum not crested •. Todirostrum (p. 361) 



ii. Bill relatively smaller (exposed culmen much less than one-fourth, 



sometimes less than one-fifth as long as wing, narrower and more ' 



tapering terminally; pileum crested. 



j. Feathers of crest blended, unicolored (whole pileum rufous); 



exposed culmen much more than one-fifth as long as wing; 



under parts, except throat, bright yellow, the latter not 



streaked Poecilotriccus (extralimital) b 



jj. Feathers of crest distinctly outlined, bicolored (black, mar- 

 gined with gray or tipped with rufous or tawny); exposed 

 culmen not much if any more than one-fifth as long as wing; 

 under parts of body very pale yellow or whitish, the throat 



streaked Lophotriccus (p. 369) 



hh. Bill smaller, the exposed culmen but little if any longer than mid- 

 dle toe with claw Orchilus (extralimital) c 



gg. Three or four outer primaries greatly reduced in size, the eighth 

 shorter than first. 



a The only genera of Tyrannidse belonging to the geographic field of this work pos- 

 sessing all but one of the above combination of characters are Placostomus and Platy- 

 triccus, which have the lull excessively broad (its width at frontal antiae much greater 

 than distance from nostril to tip of maxilla) and Nesotriccus, which has the tail more 

 than seven-eighths as long as the wing. 



bPoedlotriccus Berlepsch, Journ. fiir Orn., July and Oct., 1884, 298, footnote. (Type, 

 Todirostrum lenzi Berlepsch.) I am not sure that the species upon which the charac- 

 ters given above are based is really P. lenzi, since it does not agree with Doctor Sclater's 

 description nor indeed any other described in vol. xiv of the "Catalogue of Birds in the 

 British Museum." It is evidently at least closely related to both P. lenzi and P. rufi- 

 gene, but apparently differs from both in having a broad and very distinct band of 

 dusky across the chest, separating the white of the lower throat from the yellow of the 

 breast. 



c Orchilus Cabanis, in Tschudi's Fauna Peruana, Aves, 1846, 164. (Type, Eus- 

 carthmus cinereicollis Maximilian ^ Platyrhynchns auricularis Vieillot.) — Orcheibis 

 (emendation) Gray, Hand-list, i, 1869, 349. (Central Peru to southeastern Brazil; 

 two species.) 



