Key to Subspecies.
A. Upper parts dark slaty-grey, crown next
forehead broadly blackish C. p. pectoralis, p. 92.
B. Upper parts ashy slaty-grey, crown next
forehead narrowly blackish C. p. confusa, p. 93.
The Fauna Of British India, Including Ceylon And Burma-birds(second Edition)
Baker, EC S (1922–1930) The fauna of British India including Ceylon and Burma. Second edition. vol.2 1924.
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