BIRDS FROM SIAM AND THE MALAY PENINSULA 231 



MICROPTERNUS BRACHYURUS WILLIAMSONI Klosa 



Micropternus brachyurus williamsoni Kloss, Ibis, 1918, p. 107 (Koh Lak, south- 

 western Siam). 



One female, Koh Lak, June 25, 1933; one female, Pran, April 3, 

 1931; one male, Knong Phra, April 16, 1929; one male and three 

 females, Pak Chong, May 2, 1926, December 21, 22, 1926; one female, 

 Chantuk, June 16, 1934; one male and one female, Pang Sok, August 

 14, 24, 1926; one male and one female, Tha Chang, March 19, 1927; 

 one male, Nakon Panom, March 8, 1929; one male. Ban Den Muang, 

 February 25, 1929; one female, Sakon Nakon, March 15, 1929; one 

 male, Klong Yai, Sriracha, July 29, 1932; one male, Kao Sabab, 

 November 8, 1933. 



I am not sure that the specimens from eastern Siam, where the 

 majority of birds in the above hst come from, really belong to this 

 form. They do not agree with the type, but they are nearer to it 

 than to phaeoceps. 



The series from eastern Siam is very variable; about two-fifths of 

 the specimens have the backs unbarred and the barring on the wings 

 much reduced; the throat in some specimens is the same color as the 

 chest and the bufl'y edges to the feathers are much reduced, while in 

 other specimens the centers of the throat feathers are much darker 

 than the chest and the huffy edges to the feathers are broad and 

 pronounced. The black barring on the belly is much reduced in the 

 majority of the series. The type of williamsoni comes from an 

 intermediate locality and the form is intermediate. 



The male from Kao Sabap is quite different from the remainder of 

 the series, and it is very doubtful if it belongs here, but I do not know 

 where else to place it. The pileum is clove brown, unmarked; it is 

 the only specimen in the series so marked, though the female from 

 Sakon Nakon approaches it somewhat. 



Eight males from central, eastern, and southwestern Siam measure: 

 Wing, 124-131 (127); tail, 61-65 (63); culmen, 24.5-27.5 (25.9) mm. 



The type of williamsoni: Wing, 117.5; tail, 61; culmen, 24 mm. 

 One female from Koh Lak and one female from Pran: Wing, 125-128; 

 tail, 59-63; culmen, 24.5-27.5 mm. Six females from eastern Siam: 

 Wing, 120-129 (124.8); tail, 58-65 (62.2); culmen, 23-26.5 (24.6) mm. 



If my views are correct, the range of williamsoni would be south- 

 western Siam through southern Siam to eastern and southeastern 

 Siam. 



Baker ^ records specimens from Meklong, Bangkok, and Samkok, 

 central Siam. Herbert ^^ reports finding two nests in the Bansakai 

 gardens and describes the eggs but unfortunately does not give the 

 dates. 



«» Journ. Nat. Hist. Soc. Siam, vol. 3, p. 424, 1919. 



•1 Journ. Siam Soc. Nat. Hist. Suppl., vol. 6, p. 323, 1926. 



