362 



BULLETIN 17 2, UNITED STATES NATIONAL MUSEUM 



PTEBUTHIUS AERALATUS AERALATUS Tickell 



Pteruthius aeralatus Tickell, Journ. Asiat. Soc. Bengal, vol. 24, p. 267, 1855 

 (Tenasserim). 



Two males, Doi Angka, 4,000 feet, December 3, 1928; ten males and 

 six females, Khun Tan Mountains, 4,000-4,500 feet, November 21-22, 

 1928, October 16, 1929, August 24-September 2, 1930, February 27- 

 March 4, 1932, May 12-15, 1933; five males and five females, Doi 

 Nangka, November 3-21, 1930, April 24, 28, 1931; one male and two 

 females. Pang Meton (Doi Nangka), May 4, 1931; two males and 

 one female, Doi Kiew Koh, December 25, 1932; one male, Doi Mana, 

 December 30, 1932; five males and five females, Doi Hua Mot, 

 August 12-September 27, 1934; three males and one female, Kao 

 Luang, 4,000 feet, Nakon Sritamarat, July 20, 1928. 



Dr. W. L. Abbott collected three males and two females, Kao Nom 

 Plu, 3,000 feet, Trang, February 20-26, 1897. He gives the foft 

 parts as: Iris grayish blue; bill black above, leaden blue beneath; feet 

 pale pinkish fleshy. 



The six males and three females from Peninsular Siam when com- 

 pared with the large series from northern Siam in the case of the males 

 are somewhat darker on the mantle and back, and in the case of the 

 females the pileum is a dingier gray and the white tips to the primaries 

 more reduced. The Peninsular birds are also smaller, but whether 

 the differences are sufficient to found a race upon, I am doubtful. 



Table 3. — Average measurements of Pteruthius aeralatus 



Specimens 



Ten males from northern Siam 



Six males from Peninsular Siam 



Ten females from northern Siam 



Three females from Peninsular Siam 



Wing 



Mm 

 79 

 74.6 

 80 

 73.8 



Tail 



Mm 

 65.4 

 60 

 56.5 

 48.7 



Culm en 



Mm 

 14.7 

 14.3 

 14.7 

 14.3 



The young male at first resembles the female. The tail and wing 

 then become like the adult male, then the back. The black of the 

 head apparently is not acquu'ed until much later; one young male has 

 begun to turn black on the auriculars. All the young males have the 

 under tail coverts washed with light yellow, but how long this is 

 retained is uncertain. 



Recently authors generally have been treating aeralatus as a form 

 of P. flaviscapis of Java, but in my opinion the latter is distinct 

 enough to rank as a separate species. There are two additional races 

 of aeralatus on the continent, however: P. a. ricketti, of southern and 

 southwestern China, a larger and grayer bird below than aeralatus, 

 and P. a. annamensis, of the Langbian Plateau, southern Annam, 



