A COLLECTION OF BIRD-SKINS FROM SIAM. 195 
3322 Hinlap, E, Siam, 8-9. 12. 15. 
S 2 Klong Bang Lai, 16-20. 1. 16. 
This magnificent series of no less than 18 specimens of Gylden- 
stolpe’s Bulbul is most interesting, as it shews (Kloss points this out 
also, “ Ibis” 1918, p. 201) that this bird is nothing but a sub-species of 
the Indian Black-headed Yellow Bulbul, Otocompsa flaviventris. Of the 
above specimens the majority have not attained the wonderful crimson- 
scarlet throats possessed by the fully adult bird in complete plumage, 
the throats being all black as in typical flaviventris. Indeed, so exact 
is the resemblance between O. f. johnsoni and small O. f. flaviventris 
that I found four Siam specimens of the former, in a box of the latter 
in the British Museum collection. 
The red throats are not sexual, for males and females alike 
possess them. It is almost certainly a sign of age however, for all the 
specimens which have no red on the throat have the black feathers of 
this part rather sparse and ragged, and possibly the complete red 
throat is not fully developed until the bird is two years old. In one 
instance of four birds shot all together at Hinlap on the 8th December, 
two have red throats and two have black, shewing no trace of red, 
Another .specimen has the throat entirely black except for one red 
feather. 
A few specimens in Mr. Herbert’s series have the yellow of the 
underparts tinged with bronze, but a similar character occurs in 
flaviventris here and there over the whole of its range, and is conspicu- 
ous in specimens in the Museum from Simla and Assam. On the 
whole the upperparts of O. f. johnsoni are a darker, deeper olive-yellow 
than in O. f. flaviventris, but the difference is not sufficient to rely on. 
Kloss ( loc. cit.) has named a Yellow Bulbul from Koh Lak, 
S. W. Siam, 0. f. minor on account of its smaller size. Mr. Herbert's 
series shews, however, that Gyldenstolpe’s Bulbul is quite common in 
S. W. Siam, and we cannot, of course, have two sub-species of a resi- 
dent bird in the same area. Kloss bird can therefore, only be a young 
johnsont, an opinion in which he would doubtless have concurred had he 
had Mr. Herbert’s birds before him for examination. 
41, TRACHYCOMUS OCHROCEPHALUS, 
Turdus ochrocephalus, Gm. Sys, Nat. i, p. 821 (1788). 
2 2 Klong Wang Hip, P. Siam, 29. 9. and 4. 10. 15. 
VOL. IIL, NO. III, 1919. 
