TROCHILVS. 311 



the whole, of tho throat brilliiint 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), tho reetrices (except middle pair) 

 greenish basal!}*, black subterminally, and tipped with white. 



a'. Exposed culmen less than half as long as wing, tho bill straight. 

 V-. Middle tail-feathers narrower near end than at base. 



c'. Exposed culmen .60, or more ; outer tail-feathers without white tips in 

 adult males, 

 d'. 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 velvet}^ 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 

 bufty, and tail more forked. Young female: Similar to 

 young male, but throat without streaks, and tail more 

 rounded. Eggs .51 X -33. Hab. Eastern 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 Yeragua. 



428. T. colubris Li.nn. Ruby-throated Hummingbird. 

 e". 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 cmarginated (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. You7ig : Similar to adult 

 female, but feathers of upper parts margined terminally 



> Except Id species of Allhit. 



