69. empidonax. 221 



Mitrephanes atriceps, Ridgio. Pr. U. S. N. M. vi. p. 413 ; id. Ibis, 

 1886, p. 461. 



Above fuscous olive, whole head deep black ; ring round the eye 

 white ; wings and tail blackish, wing-coverts and margins of 

 external secondaries slightly edged with whitish ; outer web of 

 outer tail-feather white : beneath pale cinereous with au ochraceous 

 tinge, throat and middle of' the belly paler; under wing-coverts and 

 inner margins of the wing-feathers whitish ; upper mandible blackish, 

 lower whitish ; feet black : whole length 4 inches, wing 2 - 2, tail 2. 

 Female similar. 



Hub. Costa Eica and Veragua. 



A very distinct species, easily recognizable by its black head and 

 the white outer web of the external pair of rectrices. 



a. Ad. sk. Irazu district, Costa Rica {Rogers). Salvin-Godman Coll. 



b, c. Ad. sk. Southern slope of the Volcan de Salvin-Godman Coll. 



Chiriqui {Arce). (Types of the species.) 



69. EMPIDONAX. 



Type. 

 Empidonax, Cab. J. f. 0. 1855, p. 480 E. pusillus. 



" Tarsus lengthened, considerably longer than the bill, and ex- 

 ceeding the middle toe, which is decidedly longer than the hind toe. 

 Tail very slightly forked, even or rounded, a little shorter only 

 than the wings, which are considerably rounded ; the first primary 

 much shorter than the fourth. Head moderately crested. Colour 

 olivaceous above, yellowish beneath, throat generally grey." (N. A. 

 B, ii. p. 362.) 



In this and the succeeding genera I have followed the arrange- 

 ment and borrowed the words of the Ornithologists of the United 

 States as closely as possible. They have had much better oppor- 

 tunities of studying these difficult birds, and I am quite content to 

 follow in their wake. 



Mr. Eidgway has been kind enough to examine for me and correct 

 the determinations of the whole of my series of the genus Empidonax, 

 and I have kept closely to his views*. 



Empidonax is most abundant in North and Central America, but 

 also extends through South America to Argentina. 



Key to the Species. 



A. Width of bill at nostrils decidedly greater 

 than half the length of the exposed 

 culmen. 



«. Lower surface deep buff 1. fulvifrons, p. 222. 



b. Lower surface whitish or yellowish. 

 a'. Upper surface umber-brown. 



a". Flanks and crissum buff 2. albigularis, p. 223. 



* See his paper on Empidonax, Ibis, 1S66, p. 461. 



