394 BULLETIN 186, UNITED STATES NATIONAL MUSEUM 



This species has the upperparts olivaceous-brown, with an indistinct 

 chestnut-rufous nuchal collar ; a white supercilium, extending to the 

 nape; the lores, feathers immediately below the eye, and ear coverts 

 black; at either side of the neck, following the ear coverts, a con- 

 spicuous patch of bright chestnut-rufous, connected with the nuchal 

 collar; the underparts white, changing to olivaceous-brown on the 

 lower flanks and the under tail coverts; the sides of the breast and 

 the upper flanks frequently (in our provinces) more or less streaked, 

 or at least suffused, with chestnut-rufous. 



I have elsewhere discussed the geographical variation of this scimi- 

 tar babbler in Thailand (Auk, 1942, p. 117) . 



POMATORHINUS SCHISTICEPS HUMILIS Delacour 



Bas-Laos Yellow-billed Scimitar Babbler 



Pomatorhinus schisticeps humilis Delacour, L'Oiseau et la Revue Franchise 

 d'Ornithologie, new ser., vol. 2, No. 3, 1932, pp. 424-425 (Thateng, Bas-Laos). 



I collected specimens, inseparable from topotypes of hwmlis, at 

 Ban San Pa Haeng and Ban Wang Mo, localities on the Mae Nan, and 

 also on Phu Kha at 4,500 feet. It seems to be really a lowland 

 bird, and its presence on Phu Kha (together with a number of other 

 species characteristic of feeble elevations), at an old hai overgrown 

 with Bubus, may well have been a result of the clearing of forest by 

 the Yao. 



In the river valley I found this form in small flocks in extensive 

 jungles of bamboo and always in company with Gampsorlxynclius. 

 In the absence of undergrowth beneath the clumps, it was possible 

 to observe the bird as it fed upon the ground, something unusual in 

 the genus, but it made up for it by greater wariness. 



A juvenile was taken on Phu Kha, April 4, 1936. 



An adult male had the irides gray; the bill yellow, with the narial 

 membranes blackish brow n ; the feet and toes plumbeous ; the claws 

 horn. 



From ripponi, the present race is distinguished by its generally 

 lesser size and smaller bill and by having the sides of the body dull 

 olivaceous-brown without any rufous suffusion. 



NAPOTHERA CRISPIFRONS CRISPIFRONS (Blyth) 



Tenasserimese Limestone Babbler 



Turdinus crispifrons Blyth, Journ. Asiat. Soc. Bengal, vol. 24, 1855, pp. 269- 

 272 (mountainous interior of Tenasserim ; type specimen from Muleyit, fide 

 Sclater, Ibis, 1892, p. 76). 



Gypsophila crispifrons, Williamson, Journ. Nat. Hist. Soc. Siam, 1916, p. 59 

 (Muang Song).— Gyldenstolpe, Ibis, 1920, p. 481 (Muang Song). 



