The genus Pteruthius contains four species and many subspecies of a very curious group of birds rather Shrike-like in general outward appearance but quite unlike any Shrikes in habits and nidification and also in the sexes being dissimilar. Harington (Journal B. N. H. S. xxiii, p. 655, 1915) suggests that the proper position of this and the preceding genus is somewhere near the Campephagidae but, though they may in some respects approach this family, they seem to me to be nearer the Timaliidae, in which I retain them.
The bill is about one-half the length of the head, strongly hooked at the tip and with the margins sinuate; the rictal bristles are weak. The nostrils are the same as in Liothrix lutea as are also the wing and tail but the upper tail-coverts only reach to the middle of the tail. The feathers of the crown are ample but do not form a crest, the tarsus is strong and quite Timaliine.
Key to Species and Subspecies.
A. Inner secondaries chestnut.
a. Crown black P. erythroptera, , p. 331.
b. Crown bluish grey P. erythropteras, , p. 332.
B. Inner secondaries golden yellow P. aeralatus aeralatus,
C. Inner secondaries tipped with chestnut P. ae. aeralatus, p. 333.
D. Inner secondaries bluish grey or green.
c. Crown greenish yellow.
a1. Nape bluish-ashy. [p. 333.
Tips of wing-coverts white .... P. melanotis melanotis,
b2. Tips of wing-coverts salmon-pink P. m. melanotis, p. 334.
b1. Nape greenish yellow.
c2. Tips of wing-coverts white .... P.m. intermedius, , p. 335.
d2. Tips of wing-coverts salmon-pink P. m. intermedius, , p- 335.
d. Crown blackish. [chloris, p. 335.
c1. No white ring round eye P. xanthochloris xantlto-
d1 A white ring round eye..- P. x. pallida, .
e. Crown dark grey.
e1. No white ring round eye P. x. xanthochloris, p. 336.
f1 .A white ring round eye P. x. pallida,
f. Crown pale ash-grey P. x. occidentalis, p. 336.
g. Crown pale greenish grey P. x. occidentalis, p. 336.
P. x. pallida (David, Yunnan) is very likely to be found in the N. Shan States, so is included in the key.