Muscicapa atra Hermann, Obs Zool ,p. 208 (1804) (Tranquebarica) is unfortunately preoccupied by Muscicapa atra of Gmelm, 1789. The next earliest name is that of Vieillot, Dicrurus macrocercus, which must therefore be used.
The Common Black Drongo is found over an area extending from Western India to a great part of China in the East, and from the Himalayas in the North to Ceylon and Java in the South. As might be expected, there is a certain amount of variation coincident with geographical area but these variations are almost entirely those of size and of comparative length of wings and tails, which makes it very difficult to define the various subspecies. I have already dealt with the Dicruridae at length in ' Novitates Zoologies,' xxv, p.296 et seq., and here only summarize my remarks.
Key to Subspecies.
A. Medium size ; wing average 140 mm.;
tail 154 mm ; culmen about 22.3 mm. D. m. macrocercus p. 356.
B. Large size; wing average 149 mm.;
tail 160mm.; culmen about 23.5 mm. D, m. albirictus. p. 337.
C. Very small size; wing average 133 mm.;
tail 153 mm.; culmen about 20 mm. D. m. minor, p. 338.
D. Medium size with short tail; wing
average 148 mm.: tail 147 mm.;
culmen about 22 mm D. m. cathaecus, p 338.
E. Size very small with long tail; wing
average 129 mm.; tail 140 mm.;
culmen about 21 mm D. m. longus, p.339.