Key to Subspecies.
A. With a white supercilium I. c. cyanura, p. 99.
B. With a blue supercilium.
a. Darker above I. c. rufilata, p. 100.
b. Paler above I. c. pallidiora, p. 101.
C. No distinct supercilium.
c. Rump light greyish blue I. c. cyanura, p. 99.
d. Bump bluish green.
a1. Above rufous olive-brown I. c. rufilata, p. 100.
b1. Above paler olive-brown I.e. pallidiora, p. 101.
Thayer and Bangs in 1914 described in the Bull. Mus. Comp. Zool. (lviii, p. 292, Loukaochai) an Ianthia, from Yunnan, as new and state that it differs from J. c. rufilata in being darker, the shoulder-patch brighter and the bases of the superciliary stripe white instead of dusky. This so-called new species, Ianthia practica, so far as I can see, differs in no single respect from typical rufilata from Nepal to Assam and it is possible that the authors compared their specimens with birds from farther west, which are obviously much paler, more especially the females. There are very large series of these birds in the British Museum from Nepal, Sikkim, Upper Burma and Yunnan, and though these vary inter se to a slight extent, I can see no constant differences in plumage correlated to any special area. The shoulder-patch varies considerably individually but Yunnan specimens certainly do not have it brighter than Nepal birds—indeed, Rothschild (Nov. Zool. xxviii, p. 39) finds the reverse is the case. The bases of the superciliary feathers are dusky in some birds, white in others.
In trying to find differences between Nepal, Burmese and Yunnan birds I have, however, confirmed an opinion already expressed by Mr, N. Kinnear that the birds West of Nepal are much paler than the Eastern form, and I therefore here describe these birds as a new subspecies.