THE BIRDS OF SOUTH-WEST AND PENINSULAR SIAM. 167 



Mesobucco cyanotis orientalis, Robinson, Ibis, 1915, p, 738, from the 

 Siamese south-eastern frontier, is synonymous with it, as Mr. Stuart 

 Baker has already shown. On the other hand, Peninsular Siam 

 birds south to Perils (thirteen adult birds examined) differ from the 

 types of M. d. cyanotis and M. c. orientalis in being distinctly 

 smaller with the wing apparently always under 80 mm. The black 

 throat-spot is always obsolescent and the ear-coverts almost unmixed 

 verditer blue, except in the bird from Perils which is approaching 

 M. d. duvauceli. We have named this form, as above, M. d. stuarti. 

 Stuart Baker has named the bird from Klang, Selangor, C. d. 

 rohinsoni, giving as the range the whole of the Malay Peninsula, 

 and stating that the ear-coverts are mixed blue and black and the 

 black spot on the breast small. As regards birds from Perak, 

 Selangor and further south, this is however not the case : somewhat 

 immature birds, in which the black forehead is not sharply defined, 

 have frequently the ear coverts mixed with blue, but fully adult 

 birds often have them as black as in specimens from Sumatra and 

 Borneo.^ In very many south Peninsula birds the black spot on the 

 breast is fully as pronounced as in Bornean examples, of which we 

 have a very large series. Sumatran birds are rather* smaller and 

 are Mesobucco duvauoeli duvauceli (Less,), while the Malayan bird, 

 wing 73-79, and the Bornean, wing 72-76, if any division is to be 

 made, will have to be known as 31. d. borneensis Parrot ( Abhandl. Ak. 

 Wissensch. Math. Phys. Miinchen, 1907, Kl. xxiv, pp. 149, 288). We 

 have seen no birds from South Patani, nor are any on record ; but, 

 since Perils examples are intermediate, they may possibly belong to 

 the southern race. 



Perhaps very large series of birds from the British portion of 

 the Malay Peninsula and from Borneo may make it possible to retain 

 the name M. d. robinsoni for the former, but on the very consider- 

 able numbers now in our possession we are quite unable to separate 

 them. 



I. Gyldenstolpe, Kungl. Sv. Vet. Akad. Handl. M. Baker, Journ. N. H. Soc. Siam, iii, 1919. 



56, No. 2, 1916. (ttrst part). 



J. Robinson, Journ. F. M. S. Mus. vii, 1917 Baker, Journ. N. H. Soc. Siam, iii, 1919. 



K. Kloss, Ibis, 1918. (second part). 



L. Robinson and Kloss, Journ. N.H. Soc. Siam, M.I. Baker, Journ. N. H. Soc. Siam, iv, 19i20. 



iii, 1919. (third part). 



VOL. V, NO. 2, 1922. 



