394 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



tipped with green or dusky; lateral rectrices extensively white, at 

 least on inner web. Adult males with under parts bright metallic 

 green, the under tail-coverts white; females with under parts pale 

 gray or grayish white, glossed with green on sides. 



Range. — Southern Mexico to western Panama. (Three species.) 



KEY TO THE SPECIES OF EXJPHERUSA. 



a. Under parts (except under tail-coverts) metallic green. {Adult males.) 



h. Only two pairs of lateral rectrices with white on inner webs, the outer webs 

 black or partly black, 

 c. Outermost rectrices wiih outer web wholly black. {Ewpherusa eximia.) 

 d. Smaller (wing averaging 58.7, tail 33.5, culmen 17. C); line of demarcation 

 between black and white on inner web of lateral rectrices sharply defined, 

 nearly transverse. (Guatemala to Nicaragua.) 



Eupherusa eximia eximia, adult male (p. 394). 

 dd. Larger (wing averaging 60.7, tail 34.7, culmen 18.7); line of demarcation 

 between black and white on inner web of lateral rectrices indistinct, 

 oblique. (Southeastern Mexico.) 



Eupherusa eximia nelsoni, adult male (p. 396). 

 cc. Outermost rectrices with outer web white next to shaft, the edge black. 

 (Costa Rica and western Panamd.) 



Eupherusa egregia, adult male (p. 396). 

 bb. Four pairs of rectrices with white on inner web, the outer web and tip of inner 

 web gray. (Southwestern Mexico.) 



Eupherusa poliooerca, adult male (p. 397). 

 aa. Under parts dull white or pale gray. (Adult females.) 



b. Lateral pair of rectrices with a broad blackish tip, extending entirely across 

 both webs and including shaft. 



Eupherusa eximia eximia, adult female (p. 395). o 



66. Lateral pair of rectrices white, including tip, narrowly edged, in part, with 



dusky, the shaft entirely white. 



c. Middle rectrices bronzy passing into dusky terminally; outermost rectrix 



white, the outer web edged terminally with dusky; second rectrix broadly 



margined for terminal half with black. 



Eupherusa egregia, adult female (p. 397). 

 cc. Middle rectrices bronze-green narrowly margined with dusky; outermost 

 rectrix white, the outer web narrowly edged subterminally with dusky, the 

 Becond similar, but with dusky sub terminal spot on edge of inner web. 



Eupherusa poliocerca, adult female (p. 398.) 



EUPHERUSA EXIMIA EXIMIA (Delattre). 



STRIPE-TAILED HUMMING BIRD. 



Adult male. — Above bright metallic grass green, usually becoming 

 more bronzy posteriorly, the up])er tail-coverts sometimes distinctly 

 bronze; middle rectrices dark bronze-green or greenish bronze; two 

 lateral rectrices (on each side) with outer web black, faintly glossed 

 with bronzy, inner web pure white veiy broadly and abruptly tipped 

 with black; remaining rectrices with outer web dark bronze or bronze- 

 green, inner web black; i)rimaries purplish dusky, the innermost with 



a The female oi E. e. nelsoni not seen. 



