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. 
J. 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............2.0.2ece cece cece eees 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 
WOlOW s cisitsite agora ee itera bul does a tenietals Heliodoxa (p. 570). 
gg. Tarsal feathering much developed posteriorly, forming a conspicuous 
fringe-like tuft; rectrices relatively broader, with tip subtruncate. 
h. Longest upper tail-coverts reaching to end of middle rectrices in 
adult male, nearly as far in female..........- Florisuga (p. 575). 
hh. Longest upper tail-coverts reaching but little more than halfway 
to tip of tail.-..2.22.2222..2.- Melanotrochilus (extralimital).¢ 
Jf. 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 without metallic color on 
COA Gt haben eave caesar libel teens ake 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 subterminally (subspatulate); adult male with 
feathers of throat very narrow, pure white basally. 
Stellula (p. 587). 
w#. Rectrices not broader subterminally, 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. 
&. 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 rufousiccsccaceseusee ve aecatcus. Atthis (p. 591). 
@ Melanotrochilus Deslongchamps, Guide d. Naturaliste, 1880, 7. (Type, Trochilug 
fuscus Vieillot.) 
