TROCHILUS. 311 
the whole, of the throat brilliant metallic (sometimes top of head similar), the 
tail-feathers (except middle pair) without white tips’ or green bases. Adult females 
and young with chin and throat dull whitish, or pale grayish (sometimes spotted 
centrally with the metallic color of the male), the rectrices (except middle pair) 
greenish basally, black subterminally, and tipped with white. 
a', Exposed culmen less than half as long as wing, the bill straight. 
b'. Middle tail-feathers narrower near end than at base. 
c', Exposed culmen .60, or more; outer tail-feathers without white tips in 
adult males. 
@', Outer tail-feather not decidedly shorter than middle pair, and not 
conspicuously narrower than the next; adult males with six in- 
nermost quills abruptly much smaller and narrower than the 
rest, the top of head greenish like back, or dusky, the tail- 
feathers (except middle pair) pointed. (Subgenus Trochilus.) 
e'. Adult male: Chin, only, opaque velvety black, the rest of the 
gorget intense metallic crimson, changing to golden red; 
tail forked for about .30-.35; length about 3.07-3.25, wing 
1.60, tail 1.25, exposed culmen .55-.65. Adult female: Tail 
double-rounded, the outer feathers about as long as middle 
pair (sometimes a little shorter), the middle pair wholly 
green, the rest green basally, then black, the three outer 
pairs broadly tipped with white; length about 3.50-3.85, 
wing 1.80, tail 1.20, culmen .70. Young male: Similar to 
adult female, but throat streaked with dusky, feathers of 
upper parts more or less distinctly margined with pale 
buffy, and tail more forked. Young female: Similar to 
young male, but throat without streaks, and tail more 
rounded. ggs 51 .83. Hab. Kastern United States, 
north to lat. 59° N., west to Great Plains, south, in winter, 
to Bahamas, Cuba, Porto Rico, eastern Mexico, and Central 
America, to Veragua. 
428. T. colubris Linn. Ruby-throated Hummingbird. 
é. Adult male: Chin and throat opaque velvety black, bordered 
below by a broad band of metallic violet, changing to 
green and blue; tail slightly forked, or emarginated (depth 
of fork only about .10 of an inch); length about 3.30- 
3.75, wing 1.70-1.75, tail 1.25, culmen .70-.75. Adult 
female: Tail much rounded, the middle feathers about the 
longest; plumage’ not essentially different from that of 
female T. colubris ; length about 3.90-4.10, wing 1.90-2.00, 
tail 1.25-1.35, culmen .78-.80. Young: Similar to adult 
female, but feathers of upper parts margined terminally 
1 Except in species of Atthis. 
