1919-] Oriental Woodpeckers and Barbels. 191 



between the two forms is very slight, and, indeed^ I can 

 trace no difference beyond the fact that erythropygius has 

 a wliite or whitish bill, and nigrigenis has a dark horny- 

 colonred bill. 



The alleged difterences are (1) position and extent of led 

 cap, (2) depth of yellow colouring below, (3) whitish or 

 dark colour of bill. 



The red of the head in the type of erythropygius is exactly 

 matched by many specimens of nigrigenis from Burma, and 

 this feature varies very greatly: thus in two birds from the 

 same area we have two adult males ; in one the red crown 

 commences about 6 mm. from the bill, and extends back for 

 about 25 mm.; in the second it commences a full 10 mm. 

 back, and only extends for about 15 mm. In comparative 

 size the red cap of the first is treble that of the second. 



As regards tiie brightness of the yellow underparts, this 

 character is equally variable and valueless, whilst some 

 nigrigenis are much brighter, many are duller than the type 

 of erythropygius. 



The third and best distinction, the colour of the bill, is as 

 follows : — In the type, which is a dismounted bird, the bill 

 has been painted j)ui'e ivory-white, but under the paint it is 

 a pale dull yellow, slaty on the gonys and also on the base 

 of the lower mandible and on the upper mandible just 

 beyond the nostril. The bill of the male in the Tring 

 Museum is ivory-white. 



Mr. Herbert^s birds and one collected by Hume at 

 Meklong, Siam, are nearer erythropygius than nigrigenis, if 

 the two forms are divisible. The male has the bill slaty- 

 horny, the lower mandible nearly all yellowish white, and 

 the upper mandible splashed with the same. The females 

 have the bill very pale ; in one it is all a dirty horny white 

 with dark base and a dark streak running through the 

 nostril exactly as it does in the type. 



The bills of nigrigenis are generally horny black, or dark 

 horny, but in many cases they are more or less marked with 

 yellowish white, and this occurs in specimens from areas as 

 far apart as Pakjan, Kolidoo, and Thoungyeen. 



