a1. Bill orange red.
b1. No blue on crown.
c1. Red on head confined to the forehead.
d1. Rectrices dark green above, with very little if any blue.
e1. Interscapular region golden yellow, more or less tinged
with orange; in the adult male a red patch on throat and
cheeks green; in female no red patch on throat; cheeks and
chin bluish. ... chrysonotus (p. 288)
e2. Interscapular region green, with no golden orange tinge;
cheeks green in the male, bluish in the female.
f1. A golden-orange band on hind neck, more or less
orange-yellow on the crown.
g1. Vertex bright orange-yellow, sharply defined in
the male; slightly tinged with orange and cheeks blue
in female.
h1. Orange crown-patch larger. ... regulus (p. 288)
h2. Orange crown-patch smaller. ... bournsi (p. 289)
g2. Vertex and hind neck with a very slight yellow
tinge, both in males and females; female like that of
regulus. ... philippensis (p. 290)
f2. No orange band on hind neck or at most only a trace;
red of forehead ending sharply against bright green of
crown. ... mindorensis (p. 290)
d2. Rectrices dark green above, lateral rectrices deep blue
toward the tips. ... siquijorensis (p. 291)
c2. Red on head continuous from forehead to nape and becoming
orange on nape.
d1. Crown-patch wider, spreading out posteriorly and ending
broadly.
e1. Back less heavily washed with golden yellow. ... apicalis
(p. 292)
e2. Back more heavily washed with golden yellow. ... dohertyi
(p. 292)
d2. Crown-patch narrower, tapering sharply to a point
posteriorly. ... worcesteri (p. 293)
a2. Bill black.
b1. A deep blue spot on middle of crown. ... galgulus (p. 294)
b2. No blue on crown. ... bonapartei (p. 294)