318 BULLETIN 17 2, UNITED STATES NATIONAL MUSEUM 



1932; one male and one female, Ban Tarn Dam, March 7, 1930; one 

 male, Hupbon, October 26, 1931; two males, Kao Sabap, October 

 28 and November 16, 1933; five females, Kao Seming, Krat, October 

 11-17, 1928, January 2, 1930. 



In this very large series there are two phases, one in which the 

 flanks are strongly hazel and the under tail coverts somewhat darker 

 and one in which the flanks are very lightly washed with hazel or 

 almost white and the under tail coverts gray. On an average the 

 specimens from the east and southeast have the whitest flanks while 

 those from the north, west, and southwest have the flanks more hazel 

 and less often v/liite, though in Kanburi specimens with strong hazel 

 flanks and others with nearly white occur together. It is my belief 

 that the birds with hazel flanks are intergrades toward 6. I. berlangeri 

 and that the latter does not reach Siam at all. There are specimens 

 in the United States National Museum from Raheng in which the 

 red-flanked bird has been identified as berlangeri and the white- 

 flanked one as diardi. Two such closely related forms would hardly 

 be found together, and some other explanation has to be sought. The 

 deeply hazel-flanked birds are in the minority. In a pair of speci- 

 mens from Tonkin before me the female has the flanks as deeply 

 hazel as any specimen from western Siam. 



There are several immature specimens in the series and the flanks 

 have only a sliglit brownish tinge. It may be the white flanks are an 

 age character, but unfortunately all the immatures in the series are 

 from eastern Siam where the form has a tendency to be white-flanked 

 anyway. 



Dr. Smith describes the soft parts as: Iris reddish brown; bfll black; 

 legs light blue. 



One set of three eggs was taken at Lat Bua Kao, August 9, 1929, 

 and one egg at Ban Foe Hilom, March 3, 1929, both with the female 

 parent. One set of two eggs was taken at Pran, May 26, 1928, and 

 another set of two eggs at Koh Lak, June 14, 1933. 



The eggs are rounded ovate and white with considerable gloss. 

 They measure 26.7 by 22.3 to 29.6 by 23.5 mm, the smallest diameter 

 going as low as 21.6; the average of the eight eggs is 28.2 by 22.3 mm. 



Gyldenstolpe " reports finding a nest with four eggs at Chum Poo 

 on May 2. From the above the form appears to have a long breeding 

 season, extending from early in March to early in August, and prob- 

 ably somewhat earlier and later. 



Dr. Smith's large series covers the distribution in Siam fairly well, 

 which extends from Koh Lak in southwestern Siam northward to the 

 northern border and east and southeast into Indo-China. 



« Kungl. Svenska Vet.-Akad. Handl., vol. 56, no. 2, p. 54, 1916. 



