342 MESSRS. ROBINSON AND KLOSS ON 



These birds are identical with Kloss' type of D. a. siamensis. 

 The fact that cathoecus and the next subspecies D. m. thai occur 

 together at Koh Lak is difficult to explain except on the theory that 

 the latter is a resident while cathoeca migrates south to escape the 

 Chinese winter. 



In only one specimen of all the series before us is the white 

 rictal spot even faintly indicated. 



491. Dicrurus macrocercus thai Kloss. 



Journ. Fed. Malay States Mus. x, 1921, p. 208 (Koh Lak). 

 Btichanga atra, A., p. 213 (Tavoy to Malewoon) ? : C. i, p. 218 



(Tenasserim) ? 

 Dicrurus ater, G., p. 148 (Ratburi and Petchaburi) ? 

 Buchanga atra longus, K., p. 227 (Koh Lak ; Tachin) ; Kloss, 



Journ. N. H. Soc. Siam, iv, 1920, p. 54 (Annam). 

 Buchanga atra cathoecus, Robinson & Kloss, Ibis, 1919, p. 611 



(S. Annam). 



2 d , 3 9 . Koh Lak, S. W. Siam, 1-4 April 1919 [Nos. 4895, 

 4932. 4975, 5020, 5028]. 



" Iris dark brown to reddish brown ; bill and feet black". 



Total length d , 275, 296; $ , 268. 257, 277 ; wing 6 , 122, 

 135 ; 5 , 130, 122, 127 ; tail d , 158 (103), 177 (105) ; $ , 154 (105), 

 140 imp. (107), 163 (100); tarsus d , 21, 21 ; $ , 19.5, 20, 19 ; bill 

 from gape d , 24, 25 ; 9 , 23, 25, 25 mm. 



This race, which we have seen from S. Tenasserim, S. W. 

 Siam, Central Siam and South Annam, is probably a resident and 

 differs from the last in having a smaller bill and wing ; shorter median 

 tail feathers but generally longer outer ones, the tail being thus more 

 graduated and forked. 



492. Dicrurus leucophaeus mouhoti ( Wald.). 



Buchanga mouhoti, Walden, Ann. & Mag. Nat. Hist (4) v, 1870, 



p. 220 (Cambodia). 

 Buchanga inter media, W&\d.exi (nee Blyth), Journ. Asiat. Soc. Bengal, 



1875, Pt. 2, Extra Number, p. 130 (Tounghoo to Tenasserim). 

 Buchanga leiicophaea, A., p. 216 (Tenasserim town, Malewoon) ; 



C. i, p. 221 (partim : smaller birds: Tenasserim, Siam); K., 



p. 227 (Koh Lak and Lat Bua Khao). 



A. Hume & Davison, Stray Feathers, vi, 1878. E. O. Grant, Fasciculi Malayenses, iii (Birds), 1905* 



B. .MiiUer, Die Ornis der Inssl Salansa, 188'2. F. Robinson and Kloss, Diis. 1910-11. 



C. dates, Birds Brit. Burmah. Vols. i. & ii, 1883. C. frairdner, .Tourn. K.H. Soc. Siam, i, 1915. 



D. Bonhote. P.Z.S. 1901, Vol. i. H. Robinson. Journ. K. M. S. Museums, v, 1915. 



JOURN. NAT. HIST. SOC. SIAil. 



