296 NOVITATES ZOOLOGICAE XXV. 1918. 



(9) Dicrurus leucophaeus minimus .siibsp. nov. 



Type : 3 23. xii. 1874, W. V. Legge coll., Tring Museum. 



Type Locality : Ceylon. 



This is the smallest of the western forms, though much larger than the 

 corresponding form from Java. It appears to be also rather a darker bird than 

 those from Southern India, but the difference is so slight as to be neghgible. The 

 tail is much shorter on an average than the more northern birds, and this seems 

 to be consistent, for the longest tail I have measmed is only 147 mm. 



Wing average, 13r6 mm. (120-135); tail average, 139 mm. (133-147). 



Stephens's name ceylonensis (in Shaw's Gew. Zool. xiii. 2, p. 140, 1826) is only 

 another name for Levaillant's " Drongri " and therefore a synonym of leucophaeus 

 and cineraceus. There is no other name that I can find applicable to the form, 

 and I have therefore been compelled to give it a new name. 



Dicrurus ater. 



Throughout the whole of India and Ceylon, Burma, the Malay Peninsula, 

 Java, Cochin China, Siam, Gambodia, and China I can find no variation in colour 

 to assist in the division of this species into geographical subspecies, with the sole 

 possible exception of the rictal white spot which may or may not be present. 

 When making my first examination I was in hopes that the depth of colour of 

 the undersurface of the wing quills might prove a character of some use, but this 

 proves to be merely individual. 



The depth of the fork to the tail lias sometimes been referred to as a dis- 

 tinguishing feature, but this again seems to vary over every portion of this 

 Drongo's range in almost equal degree, though birds to the west of the Brahma- 

 pootra certainly have longer and more deeply forked tails on an average than 

 have those to the east of this river. 



As regards the rictal white spot, this does not help us much. Roughly 

 speaking, it may be said to be always present in birds from the North- West, 

 Central, and Southern India and in all Central and South Burmese ones as well 

 as in Malay specimens. In birds from Siam, Cochin China, and China it is 

 generally absent, whilst of those from N.E. India, Assam, Northern Burma, 

 and Formosa about half have the spot and half have not. From Java there 

 are practically no specimens with any sign of a spot. 



We are driven therefore to size as the main means for differentiating between 

 the various races, but, as with other genera and species of the Dicruridae, 

 comparative proportions of wing, tail, and bill must not be overlooked. 



The figures given below show the average measurements of specimens from 

 every portion of the Black Drongos' habitat together with maxima and minima 

 for wings and tails. 



N.W. India : 13 birds. Rictal spot present in all but one. 



Wing average, 1494 mm. (140-155); tail average, 166'4 mm. (154-184); 

 bill about 225 mm. 



N.E. India and Assam : 38 birds. Rictal spot present in 20, absent in 18. 



Wing average, HSS mm. (141-155); tail average, 158'0 mm. (14(1-178); 

 bill about 24 '0 mm. 



