88 BULLETIN 17 2, UNITED STATES NATIONAL MUSEUM 



The form breeds in the Kirghiz Steppes, Ladak, and Tibet, migrat- 

 ing south in winter to Persia, India, Siam, Malay Peninsula, Sunda 

 Islands, and eastern Africa. 



Robinson and Kloss ^^ record it from Pulo Terutau, December; 

 Robinson ^^ from Koh Pennan, June ; and Robinson and Kloss ^° from 

 Koh Lak. 



CHARADRIUS MONGOLUS MONGOLUS Pallas 



Charadrius mongolus Pallas, Reise durch verschiedene Provinzen des russischen 

 Reichs, vol. 3, p. 700, 1776 (Mongolia). 



One female, Lem Sing, Chantabun, June 9, 1926. 



Wliile breeding specimens of C. mongolus and C. atrijrons are per- 

 fectly distinct and easily differentiated, the nonbreeding birds are 

 extremely difficult. C. mongolus has a shorter tarsus; otherwise I 

 know of no certain way to separate the two forms in nonbreeding 

 plumage. The tarsi in 10 specimens of C. mongolus, measure 28.5-31 

 (29.8) mm; in six birds in breeding plumage of C. atrijrons, 32.5-34.5 

 (33.1) mm. 



There are few authentic records of C. mongolus from Siam; the 

 migration route is more to the eastward. Most of the records of 

 C. m. mongolus from Siam and the Malay Peninsula are probably 

 C. TO. atrifrons. 



Charadrius m. mongolus breeds from eastern Siberia west to 

 Mongolia and migrates south late in summer to Japan, eastern 

 China, the Philippines, Celebes, New Guinea, and Australia. 



PAGOA LESCHENAULTII (Lesson) 



Charadrius leschenaullii Lesson, Diet. Sci. Nat. (Levrault), vol. 13, p. 36, 1826 

 (Pondicherry, India). 



One female, Koh Chang, January 9, 1926; one male and one female, 

 Lem Sing, Chantabun, June 9, 1926; one male, Sriracha, February 4, 

 1927; four females, Sam Roi Yot, November 8-10, 1933. 



Dr. W. L. Abbott collected a pair at Prahmon, Trang, March 24, 

 1896, and a pair on Pulo Langkawi, December 6, 1899; also a female 

 on Loughborough Island, Mergui Archipelago, January 26, 1900. 



In Peninsular Siam it has been recorded from Koh Lak and the 

 island of Puket. Robinson and Kloss ^^ say it occurs sparingly 

 throughout the Malay Peninsula. 



The species breeds in the Ku-ghiz Steppes and northwestern Alon- 

 golia and winters as far south as Australia, the Solomon Islands, and 

 South Africa. 



«e Ibis, 1911, p. 12. 



•• Journ. Federated Malay States Mus., vol. 5, p. H2, 1915. 



" Journ. Nat. Hist. Soc. Siam, vol. 5, p. 61, 1921. 



'" Journ. Nat. Hist. Soc. Siam, vol. 5, p. 01, 1921. 



