THE BIRDS OF NORTHERN THAILAND 227 



streak of black bordering the posterior crown on either side; the re- 

 maining upperparts bright, deep green; the supercilia, sides of the 

 head, the throat, and f oreneck cerulean blue ; a patch at each side of 

 the lower neck and (sometimes) a minute speck at either side of the 

 upper throat at the base of the mandible red; the remaining under- 

 pays yellow-green ; the under surface of the tail blue-green. 



The blue-throated barbets of northern Thailand lie between asiatica 

 and davisoni. In a series of 24 birds before me, two are separable 

 from Indian specimens of asiatica only by the rather paler color of 

 the throat (like that of davisoni) , two others are indistinguishable from 

 a topotype of davisoni; the remainder have the blue of the throat as in 

 davisoni but show every degree of intergradation between the black 

 and blue vertical bars which respectively characterize the northern 

 and southern races. In almost every case the bar is as narrow as in 

 asiatica, with corresponding increase in the extent of the red frontal 

 patch. In view of their instability and the intermediate nature of 

 the characters, I feel that, at least for the present, our population 

 should be left unnamed. 



CYANOPS AUSTRALIS INVISA Deignan 



Northern Thai Blue-eared Barbet 



Cyanops australis invisa Deignan, Auk, vol. 58, 1941, pp. 397-398 (Pang Makham 



Phong, at the foot of Doi Pha Sakaeng, North Thailand). 

 Cyanops cyanotis, Gyldenstolpe, Kungl. Svenska Vet.-Akad. Handl., 1913, p. 51 



(Ban Huai Horn, Khao Phlung) ; Journ. Nat. Hist. Soc. Siam, 1915, p. 230 



(listed). 

 Mesobueco duvaugli cyanotis, Gyldenstolpe, Kungl. Svenska Vet.-Akad. Handl., 



1916, p. 100 (Khun Tan). 

 Cyanops duvaucelii cyanotis, Gyldenstolpe, Ibis, 1920, p. 598 ("Siam, north of 



the Peninsula"). 

 Mesobueco duvauceli cyanotis, de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 



1929, p. 570 (Chiang Mai, error [= Chiang Saen Kao], Doi Suthep) ; 1934, 



p. 256 (Khun Tan). 

 Cyanops duvaucellii cyanotis, Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1931, 



p. 159 (Doi Suthep) ; 1936, p. 95 (Doi Suthep). 

 Mezobucco duvaucelii cyanotis, Riley, U. S. Nat. Mus. Bull. 172, 1938, p. 207 



(Khun Tan, Doi Langka). 



The blue-cheeked barbet is an inhabitant of the evergreen from the 

 plains to about 5,500 feet ; I found it very common, especially at low 

 elevations, in the districts east of, and including, the Khun Tan range 

 and rare on the mountains of the more western provinces. 



Its small size, green coloration, ventriloquial voice, and custom of 

 perching at the very top of a high tree combine to render this bird 

 one of the most difficult to observe or collect; its presence, however, 

 may always be known by the endlessly repeated double note, too-rook, 

 too-rook, too-rook. 



