TROCIIILIDAE — THE HUMMING-BIRDS. 91 
Above glossy blackish-dusky, very decidedly paler on the rump ; 
abdomen very much paler than the back. Length, 4.50 ; wing, 4.50. 
Hob. Pacific Province of North America, south to Guatemala (from 
whence specimens are much darker, almost black above, and slightly 
smaller.) {Oregon Swift') . . . . . . . var . vauxi. 
^ Family TROCHXLIDiE. — - The Humming-Birds. “ 
Char. Least of all birds ; sternum very deep ; bill subulate, and generally longer than 
the head, straight, arched, or upcurved. Tongue composed of two lengthened cylindrical 
united tubes, capable of great protrusion, and bifid at tip ; nostrils basal, linear, and 
covered by an operculum ; wings lengthened, pointed ; first quill usually longest except 
in Aithurus, where it is the second; primaries ; 10.00; secondaries, 6.00 ; tail of ten 
feathers. Tarsi and feet very diminutive, claws very sharp. Iris brown. 
Eggs, as far as known, always white, and two in number. Nest generally saddled on 
top of a branch. Confined entirely to the New World. 
Phaethornithinse. Anterior toes connected at the base. No metallic lus- 
tre to the dull plumage. 
Trochilinss. Anterior toes not connected at the base, 
with more or less of metallic lustre, at least in .the males. 
Plumage brilliant, 
” Subfamily TBOCHILXNiEL 
Common Characters. All the North American Trocliilidce have metallic green 
backs, excepting Selasphorus rufus , this color extending over the top of head, 
except in Calypte (metallic red and violet) and Heliopcedica (bluish-black). The 
latter alone has a white stripe through the eye. Atthis heloisce alone has the tail 
tipped with white in the male. Females of all the species except Heliopcedica 
have tail tipped with white ; all have it rounded. All females lack the metallic 
throat. The males of the several genera belonging to North America may be 
distinguished as follows : — 
I. Bill covered with feathers between nostrils. 
A. Top of head green. 
Feathers of throat not elongated. 
Tail rounded or slightly emarginated, the feathers broad, rounded, and 
metallic rufous-purple, or greenish-blue. Wing more than 2.50 . Lampornis. 
Tail more or less forked ; feathers pointed, narrow, and without rufous 
or blue. Wing much less than 2.00. (Page 92.) .... Trochilus. 
Throat-feathers elongated laterally into a kind of ruff. Tail-feathers edged 
or banded with cinnamon at base. 
Tail cuneate, the outer primary attenuated at end. Innermost tail- 
feather green above. 
Tail dusky at end (Page 93.) Selasphorus. 
Tail tipped with white. (Page 93.) Atthis. 
Tail nearly even, and emarginated. Outer primary not attenuated at 
end. Innermost tail-feather brown above, (Page 92.) . . . Stellula . 
B. Top of head metallic red or violet. 
Metallic feathers of side of throat much elongated. (Page 92.) . . Calypte. 
