THE BIRDS OF NORTHERN THAILAND 291 



birds in length of wing and tail, but all are winter-taken and might be 

 visitors. My summer-taken material, on the other hand, is immature 

 and not certainly identifiable. A series of breeding adults might show 

 that the resident population is not cathoecus at all ; until specimens be 

 available, however, I must assume that our summer birds are of the 

 Chinese race. 



DICRURUS ADSIMILIS ALBIRICTUS (Hodgson) 



Himalayan Black Drongo 

 [Bhuchanga] albirictus Hodgson, India Rev., vol. 1, 1837 [= 1836], p. 326 (Nepal). 



The Himalayan race of the common black drongo occurs regularly, 

 although in small numbers, in the dry, deciduous forest on the lower 

 slopes of Doi Suthep. I took a male and a female at 1,600 feet, Decem- 

 ber 12, 1931, and a second male at 1,300 feet, February 22, 1936. 



These birds had the irides red ; the bill, feet, toes, and claws black. 



D. a. albirictus is distinguishable from cathoecus only by its rela- 

 tively longer tail. The tail length of the former ranges from 152 to 

 180 mm. ; of the latter, from 137 to 154 mm. 



The tails of my specimens, all fully adult, measure 160, 165, and 

 171 mm. Two of the three show the white rictal spot. 



DICRURUS LEUCOPHAEUS LEUCOGENIS (Walden) 



Crow-billed Drongo 



[Bhuchanga] annectans [sic] Hodgson, India Rev., vol. 1, 1837 [= 1836], p. 326 



(Nepal). 

 Dicrurus annectam, Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1936, p. 169 



(Nan Province). 



In the largely uncultivated lowlands of Phrae and Nan Provinces, 

 where I failed to find any form of Dicrurus adsimilis, the crow-billed 

 drongo proved to be extremely common in the dry, deciduous forest. 



My specimens, taken in March and September, had the gonads 

 inactive, but I have no doubt that the species breeds in those districts. 



An adult female had the irides red; the bill, feet, toes, and claws 

 black. 



In coloration this drongo resembles Dicrurus a. cathoecus of corres- 

 ponding age, but it is glossed with steel green rather than blue. From 

 cathoecus it is best distinguished by its less slender form, its much more 

 robust bill, and its relatively shorter tail, with the outermost pair 

 of rectrices more distinctly curved upward. 



DICRURUS HOTTENTOTTUS HOTTENTOTTUS (Linnaeus) 



Indian Hair-crested Drongo 



[Corvus] hottentottus Linnaeus, Systema naturae, ed. 12, vol. 1, 1766, p. 155 

 ("Cap. b. spei," error; type locality corrected to Sikkiin, by Stuart Baker, 

 Nov. Zool., vol. 26, 1919, p. 44). 



