i()i^.] recently collected in Siam. 107 



-/ 56. Micropternus brachyurus williamsoni, subsp. nov. 



1 c? ad. Koh Lak, S.W. Siam. 10 Nov. 1916. 



Iris dark ; bill plumbeous-black ; feet brownish-black. 



T.L. 230; T. 62 ; W. 112; Ta. 21 ; B. f. g. 265. 



Differs from the form inhabiting the Malay Peninsula 

 south of Lat. 9° N. (which if distinct from the Javan bird 

 will have to be known as M. b. squamigularis Sundevall^) 

 in having the dark median area of the chin and throat- 

 feathers much narrower with no pale shaft-line, and their 

 pale edges broader ; rather darker breast ; dark bars on the 

 tail (five and a black tip), though reaching the shafts yet 

 much narrower (2 ram. above and 1 mm. below, against 

 3 mm. or more above and below), and also narrower dark 

 bars on the back and wings. Size about the same, as the 

 Malayan birds vary in wing-length between 102 and 

 114 mm.; the larger wings occurring in the south as well as 

 in the north of their area. 



M. h. phaioceps differs in having the shafts of the wing 

 and tail-feathers clear brown, not barred with black; while 

 M. b. fokiensis of eastern China and M. b. holrqydi of 

 Hainan have the plumage dark brown above narrowly barred 

 with rufous. 



Where my own material has been meagre Mr. W. J. F. 

 Williamson has, in a number of instances, lent me additional 

 specimens from his own collection, and I have much pleasure 

 in naming this Woodpecker after him in recognition of this 

 assistance. 



All forms of Micropternus are, as Hartert has noted (Nov. 

 Zool. xvii. p. 221), only subspecies of brachyurus. In deal- 

 ing with continental birds — exclusive of the dark brown 

 rufous-barred races of southern China, and perhaps Tonkin 

 and northern Laos — it seems simplest to place them in two 

 sections :— (1) the brachyurus group with the shafts of the 

 wing-feathers barred or otherwise blackened, and (2) the 

 phaioceps group, in which the wing-shafts are perfectly 

 unsullied. All the southern forms belong to the first 

 * Coni=p. Av. Pic. 1866, p. 89 (ex Malacca). 



