308 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



ee. Bill not excessively compressed terminally (more linear or parallel-edged 

 in vertical profile); tomia not serrate terminally. 

 /. Larger (wing more than 60 mm.). 



g. Tarsal feathering short, not forming a fringe-like tuft posteriorly; 



rectrices relatively narrower, with tip rounded. 



h. Exposed culmen two-thirds to three-fourths as long as tail; tail not 



more than three-fifths as long as wing in adult male, less than 



three-fifths as long in female; deeply emarginate in adult male, 



slightly rounded or double-rounded in female; adult female not 



spotted below Eugenes (p. 564). 



hh. Exposed culmen slightly more than to less than half as long as 

 tail, the latter more than two-thirds as long as wing in adult 

 male, more than three-fifths as long in female, forked in male, 

 deeply emarginate in female; adult female spotted with green 



below Heliodoxa (p. 570). 



gg. Tarsal feathering much developed posteriorly, forming a conspicuous 



fringe-like tuft; rectrices relatively broader, with tip sub truncate. 



h. Longest upper tail-coverts reaching to end of middle rectrices in 



adult male, nearly as far in female Florisuga (p. 575). 



hh. Longest upi^er tail-coverts reaching but little more than halfway 



to tip of tail Melanotrochilus (extralimital).'^ 



ff. Smaller (wing not more than 50 mm.). 



g. Tail less than half as long as wing; adult male with white pileum and 



dark purplish or blackish under parts Microchera (p. 580). 



gg. Tail not less than half as long as wing; adult males with pileum 

 metallic green and under parts not dark purplish or blackish. 

 h. Exposed culmen less than one-third as long as wing; tail not more 

 than half as long as wing; adult male v/ithout metallic color on 



throat Mellisuga (p. 583). 



hh. Exposed culmen not less (usually more) than half as long as wing; 

 tail more than half as long as wing; adult males with throat 

 metallic red, purple, or violet. 

 i. Rectrices broader sub terminally (subspatulate) ; adult male with 

 feathers of throat very narrow, pm-e white basally. 



Stellula (p. 587). 

 ii. Rectrices not broader sub terminally, but more or less tapering; 

 adult males with feathers of throat broader, gray, dusky, or 

 buffy basally. 

 j. Bill straight, less than half as long as wing. 



h. Lateral rectrices little if any longer than middle pair, or else 

 (males of Calypte and Archilochus) tail forked for less than 

 half its length; adult males with tail less than three-fourths 

 wing, not forked, or else (adult males of Calypte and Archi- 

 lochus) forked for less than half its length. 

 I. Plumage with more or less of rufous; tail rounded or gradu- 

 ated in males, strongly rounded in females. 

 m. Tail less strongly rounded, none of the rectrices pointed 

 or contracted terminally; adult males with lateral 

 rectrices broadly tipped with white and with basal 

 half rufous Atthis (p. 591). 



o Melanotrochilus Deslongchamps, Guide d. Naturaliste, 1880, 7. (Type, Trochilus 

 fuscus Vieillot.) 



