762 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
longest, the tenth (outermost) very variable, sometimes not more 
than half as long as ninth, sometimes more than half as long as 
seventh (longest); tail decidedly (sometimes much) longer than 
wing, all the rectrices (except, sometimes, outermost pair) truncate 
or subtruncate at tip, the outermost pair more or less strongly bowed. 
basally. Tarsus about as long as longest anterior toe, naked for 
about lower half; inner anterior toe united to outer toe for whole of 
its first and half or more of its second phalanx. 
Coloration — Adult males with chest and upper parts (except wings) 
metallic green, bronze, or blue (head sometimes black), the wing- 
coverts and secondaries narrowly barred or vermiculated with white 
and blackish, the middle rectrices broadly tipped with black; under 
parts (posterior to chest) bright red, orange, or orange-yellow, this 
usually separated from metallic green, bronze, or blue of chest by a 
band of white; adult females with chest and upper parts brown or 
slate color. 
Range.—Rio Grande Valley and southern Arizona to eastern Peru, 
Bolivia, Paraguay, Uruguay, Cayenne, and Trinidéd. (About 
fifteen species.) 
KEY TO THE SPECIES AND SUBSPECIES OF TROGONURUS. 
a. Back, chest, etc., bright metallic green, golden green, or golden bronze. (Adult 
males.) 
b. Lateral rectrices uniform black, except the broad terminal area of white; outer 
web of primaries not edged with white. (Highlands of Mexico and Guatemala.) 
Trogonurus mexicanus, adult male (p. 765). 
bb. Lateral rectrices barred or vermiculated with white; outer web of primaries 
(except outermost) edged with white. 
c. Under parts, posterior to chest, red or orange. 
d. Lateral rectrices (three pairs) very broadly tipped with white. (Under parts 
red, rarely orange.) 
e. Lateral rectrices white, finely vermiculated or narrowly barred with black 
(except the very broad terminal immaculate area); forehead (sometimes 
crown also) black. 
J. Lateral rectrices vermiculated; middle rectrices golden or coppery; tail 
shorter (152.5-171). (Trogonurus ambiguus.) 
g. Above more golden or bronzy, the middle rectrices frequently cop- 
pery bronze; tail averaging longer (165.6 mm.). (Highlands of 
Mexico to southern Arizona and Rio Grande Valley in Texas.) 
Trogonurus ambiguus ambiguus, adult male (p. 768). 
gg. Above more greenish, the middle rectrices bronze-green to greenish 
bronze (never coppery); tail averaging shorter (155.8 mm.). (Tres 
Marias Islands, western Mexico.) 
Trogonurus ambiguus goldmani, adult male (p. 772). 
Jf. Lateral rectrices narrowly and regularly barred; middle rectrices green 
or golden green; tail longer (161.5-180.5 mm.). (Pacific slope, from 
Guatemala to Costa Rica.)..'Trogonurus elegans, adult male (p. 773). 
