306 
NORTH AMERICAN BIRDS. 
grayish, at tip and base, blue-black in 
middle portion............. ..-- Chlorostilbon, 
?, Middle tail-feathers bronzy ; females and young 
males without grayish base or tip to outer 
tail-feathers....... secsecseseeveese Sporadinus.? 
#’, Tail less than three-fourths as long as wing, 
variously shaped, but never forked for more 
than one-fourth its length; adult males vari- 
ously colored, but never entirely green, 
beneath. 
?. Lower parts pure white, the sides sometimes 
green, or spotted with green; sexes 
alike. 
j. Exposed culmen decidedly more than 
half as long as tail; top of head 
usually metallic blue or violet. 
Uranomitras 
jf. Exposed culmen not more than half as 
long as tail; top of head never blue 
OF Violet .....sccsseeeseereeeee Agyrtriast 
?, Lower parts never pure white. 
f. Tail bright bluish green or greenish blue, 
crossed near end by a broad band of 
blue-black, 
Breast and sides of head deep blue; 
throat brilliant green, the centre 
of each feather darker; sexes 
alike; wing 2.60-2.80. 
Petasophora. 
jf. Tail not bluish green, ete. 
kh. Feathering of forehead extended 
forward as far as anterior end 
of nostrils, and partly or en- 
tirely covering the scale over 
nostrils, 
1 Chiorostilbon Goutp, Mon. Troch. pt. v. 1853. Type, Trochilus pucherant Bourc. & Muts. (Three species 
in Mexico, one in Porto Rico, and about six in South America.) 
2? Sporadinua Bonap., Rev. et Mag. Zool. 1854, 255. Type, Trochilus riccordi Gerv. (One species in Haiti, 
one in Cuba and Bahamas, and apparently one peculiar to Bahamas.) 
3 Uranomitra Ruicn., Aufz. der Colib. 1853, 10. Type, Trochilus franciz Bourc. & Muts. (Four species ? 
in Mexico, one in Honduras, one in Colombia, and one in Peru.) 
4 Agyrtria Rztcn., Troch. Enum. 1855, 7%. Type, Trochilus brevirostris Less, (Two Mexican and numerous 
South American species; some of the latter with lower parts mostly green; one of the former with buffy or 
rufous belly and flanks.) 
5 Petasophora Gray, List Gen. B, 1840, 13. Type, Trochilue serrirostris ViE1LL. (One species in Mexico 
and Guatemala, several in Central and South America.) 
