BIRDS OF NORTH AND MIDDLE AMERICA. 



791 



shorter than the digit; all the claws rather strongly curved, sharp, 

 compressed. 



Coloration. — Above plain olive-green passing into sooty on pileiim; 

 a conspicuous white supraloral stripe extending to above eye; under 

 parts yellow, tinged with olive on chest and sides. 



Nidification. — (Unknov/n ?) 



Range. — Southern Mexico to Panama. (Two species.) 



KEY TO THE SPECIES OF MICROTRICCUS. 



a. Pileum slate color; white superciliary stripe extending nearly to end of auricular 

 region; whole auricular region dusky olive. (Southeastern Mexico to Costa Rica.) 



Microtriccus semiflavus (p. 791) 

 aa. Pileum dark sooty brown; white superciliary stripe not extending beyond middle 

 of auricular region; auricular region greenish olive, dusky only near posterior 

 angle of eye. (Costa Rica to northwestern Ecuador.) 



Microtriccus brunneicapillus (p. 792) 



MICROTRICCUS SEMIFLAVUS (Sclater and Salvin). 

 GRAY-CAPPED TYRANNULET. 



Adults (sexes alike). — Pileum uniform slate color; rest of upper 

 parts plain olive-green, the inner webs of rectrices, remiges, and 

 greater wing-coverts dusky grayish brown; a white superciliary 

 stripe, extending from nostrils to near end of auricular region; loral 

 region dusky or slate color; suborbital and auricular regions deep 

 greenish olive, becoming dusky on upper portion, especially next to 

 posterior angle of eye; malar region and under parts canary yellow, 

 narrowl}^ and indistinctly streaked with olive laterally, at least on 

 sides of breast; axillars and under wing-coverts sulphur yellow; inner 

 webs of remiges edged with dull yellowish white; maxilla dusky horn 

 color or brownish black; mandible similar but more grayish basally; 

 legs and feet grayish dusky in dried skins (bluish gray in life?). 



Adult waZ^.— Length (skins), 74-82 (78) ; wing, 43.5-45.5 (44.8) ; tail, 

 25-26.5 (25.8); exposed culmen, 7.5-8 (7.7); tarsus, 13.5-14 (13.7); 

 middle toe, 7.5-8.5 (8).« 



Adult />maZf.— Length (skins), 72-77 (75); wing, 44-45 (44.3); tail, 

 23-24.5 (23.7); exposed culmen, 7.5-8.5 (8.2); tarsus, 13-13.5 (13.2); 

 middle toe, 7-8 (7.7).« 



o Three specimens. 



