548 BULLETIN '■{), UNITED STATP^S NATIONAL MUSEUM. 



j. More strongly olive aliove, more decidedly yellowish beneath; 

 wing averaging longer, tail slightly shorter and relatively 

 broader; male averaging wing 67.5, tail 57.1, exposed culnien 

 11.8; female, 64.4, 55, 11.4. (Western North America, south 

 in winter to sovithern Mexico.) 



Empidonax difficilis difficilis (p. 576) 

 jj. More grayish olive aliove, i)aler yell(jwish Ijeneath; wing aver- 

 aging shorter, tail slightly longer, bill longer and relatively 

 narrower; male averaging wing 65.7, tail 57.5, exposed cul- 

 men 12.3; female, 61.7, 55.1, 11.6. (Lower California to 

 Sonora and southern Arizona.) 



Empidonax difficilis cineritius (p. 580) 

 u. Coloration darker and brighter, the uj^per parts more decidedly 

 olive-greenish, the under parts more strongly yellowish; bill 

 broader terminally, with lateral outlines more convex. (Cen- 

 tral and southern Mexico.). . .Empidonax difficilis bairdi (p. 581) 

 J}\ Bill broader, its width at anterior end of nostrils more than half the 

 length of exposed ciilmen. 

 (J. Less yellowish olive-green above, abdomen, etc., more sulphur yellow; 

 chest light olive-greenish; larger (wing 69 in male, 64.5 in female). 

 (Highlands of Guatemala and Chiapas.). .Empidonax salvini (p. 582) 

 gg. More yellowish olive-green above, abdomen, etc., canary yellow, 

 chest fulvescent; smaller (wing averaging 66.5 in male, 61.5 in 

 female). (Highlands of Costa Rica and Panama.) 



Empidonax flavescens (p. 583) 

 dd. Tarsus not more than 14.5 mm. 



c. Pileum and hindneck dark gray, in slight but obvious contrast with 

 grayish olive of back, etc.; wing-bands grayish white. (Western 



Ecuador.) Empidonax griseipectus (extralimital) o 



ee. Pileum brown or olive, concolor with back; wing-bands buff or cinnamon. 



/. Above brown; under wing-coverts buff. (Southern Brazil; Argentina; 



Paraguay.) Empidonax argentinus'? (extralimital) ^ 



a Empidonax griseipectus Lawrence, Ann. Lye. Nat. Hist. N. Y., ix, 1869, 236 (Puna 

 I., near Guayaquil, w. Ecuador; coll. U. S. Nat. Mus.); Baird, Bi'ewer, and 

 Ridgway, Hist. N. Am. Birds, ii, 1874, 365; Ridgway, Ibis, 1886, 464; Sclater, Cat. 

 Birds Brit. Mus., xiv, 1888, 225 (Bababoyo, w. Ecuador). — [Empidonax] griseipectus 

 Sclater and Salvin, Nom. Av. Neotr., 1873, 52; Sharpe, Hand-list, iii, 1901, 138.— 

 Empidochanes griseipectus Berlepsch and Taczanowski, Proc. Zool. Soc. Lond., 1883, 

 5b8 (Chimbo, w. Ecuador). 



b {1) Empidochanes argentinus Cabanis, Journ. fiir Orn., xiv, no. 93, May, 1868, 196 

 (Buenos Aires; coll. Berlin Mus.). — l\Myiobius] argentinus Gray, Hand-list, i, 1869, 360, 

 no. 5478. — fEmpidonax argentinus Berlepsch and Hellmayi", Journ. fiir Orn., Jan., 

 1905, 23 (crit.). — Empidonax brunneus (not Pipra brunnea Thunberg, Mem. Acad. Imp. 

 Sci. St. Petersb., viii, 1822, which Lonnberg, in Il)is, 1903, 242, says= Empidonax 

 bimaculatiis?) Ridgway, in Baird, Brewer, and Ridgway*s Hist. N. Am. Birds, ii, 

 1874, 363 (Rio Parana, Paraguay; coll. U. S. Nat. Mus.); iii, 1874, 519; Ibis, 1886, 

 460, 463; Sclater, Ibis, 1887, 64 (crit.). — Empidonax brunnescens (error) Salvin, Ibis, 

 1874, 309, in text (crit.). — Empidonax biinaculatns (not Muscipeta himaculata 

 D'Orbigny and Lafresnaye) Sclater, Ibis, 1887, 65, part (crit.); Cat. Birds Brit. Mus., 

 xiv, 1888, 224, part (in synonymy); Berlepsch, Journ. fiir Orn., 1887, 118 (Paraguay); 

 Ihering, Rev. Mus. Paul., vi, 1904, 326 (Paraguay); (?) Sclater and Hudson, 

 Argentine Orn., i, 1888, 155. — [Empidochanes] fuscatus (not Muscipeta fuscata Maxi- 

 milian) Sclater and Salvin, Nom. Av. Neotr., 1873, 31, part. 



