TYRANNID^— THE FLYCATCHERS. 363 



There are few sj)ecies of North American birds more difficult to distin- 

 guish than tlie small Flycatchers, the characters, though constant, being very 

 slight and almost inappreciable, except to a very acute observer. 



The following .synopsis may, aid in distinguishing the species : — 



Species and Varieties. 



A« Liner webs of secondaries edged with pinkish-bufi". 



a. Olive-brown above, whitish beneath ; tibise ochraceous. 



E. brunneus.' Third quill longest, first equal to seventh ; tail slightly 

 rounded. Russet-olive above, the crown, wings, and tail with a red- 

 dish-brown tinge ; a yellowish-gray shade across the breast, and a faint 

 sulphur-yellow tinge to posterior lower parts. Wing-bands broad, 

 sharply defined, deep ochraceous ; lining of wing and tibiie slightly 

 tinged with the same. Wing, 2.35 ; tail, 2.30 ; bill, .57 and .27 ; tarsus, 

 .56; middle toe, .33. Hob. Parana. 



E. axillaris.^ Third quill longest, first equal to seventh ; tail ? Dark 

 grayish-brown above, nearly uniform, breast ochraceous-olive; a just 

 appreciable tinge of sulphur-yellow on abdomen. Wing-bands narrow, 

 badly defined, in color nearly like the back ; lining of the wing and 

 tibise very deep ochraceous. Wing, 2.40 ; tail, 2.50 ; bill, .60 and .30 ; 

 tarsus, .60 ; middle toe, .43. Hab. Orizaba. 



h. Glive-gT'oi^n above, yellow beneath ; tibiiie greenish. 



E. flavescens.' Third, or third and fourth quills longest; first e((ual to 

 eighth. Tail decidedly emarginated. Intense greenish-olive above, the 

 crown with a decided russet tinge; beneath bright lemon-yellow, with 

 a shade of fulvous-brown across the breast. Wing, 2.35 to 2.70 ; tail, 

 2.20 to 2.40; bill, .59 and .30 ; tarsus, .66 ; middle toe, .35. Hab. Costa 

 Rica. 



E. bairdi.' Fourth quill longest, first shorter than eighth. Tail slightly 

 emarginated. Dull greenish-ohve above, nearly uniform ; beneath 

 clear sulphur-yellow, with a greenish-olive shade across the breast. 

 Wing, 2.60 ; tail, 2.50 ; bill, .62 and .29 ; tarsus, .65 ; middle toe, .35. 

 Hah. Eastern Mexico (MniADOR). 

 B. Inner webs of secondaries edged with yellowish or grayish white. 



a. Olive-green above, yellowish beneath. 



§. Young not mottled above. 



E. flaviventris. Bill broad, twice as wide as deep, and the culmen 

 less than twice the breadth. Outer web of lateral tail-feather dusky, 

 like the inner. Wing-bands narrow, whitish. Tail square. 



Clear olive-green above, sulphur-yellow beneath ; wing-bands 

 sidphur-yellowish ; lining of wing clear sulphury-yellow. Wing, 



1 Empidonax brunneus, Kidgway. A very distinct species, uot needing comparison with any 

 other. 



- Emjridonax ao-AUaris, KiiiowAY. 



' Empidanax flavesccns, Lawu. Maybe the southern form of bairdi, but dillor in some ap- 

 parently essential features. 



* Empidonax bairdi, ScLATEn, P. Z. S. 1858, 301 ; Ibis, 1859, 442 ; Catal. Am. B. 1862, 

 230. — ScLATEii & Salvi.n, Ibis, 1860, 36. {Hab. Cordova, Coban, Mazatlan, Mirador, etc.) 



