a1. White spot on first primary smaller and not reaching the shaft.
b1. White spot on outer rectrix subterminal. ... jotaka (p. 349)
b2. White spot on outer rectrix terminal.
c1. Spot on outer rectrix on inner web only; spot on second
primary not reaching the shaft. ... manillensis (p. 346)
c2. Spot on outer rectrix involving both webs; spot on second
primary reaching shaft on both webs. ... macrurus (p. 348)
a2. White spot on first primary larger and reaching the
shaft. ... griseatus (p. 344); mindanensis (p. 346)