132 BULLETIN 186, UNITED STATES NATIONAL MUSEUM 



Adults had the irides dark brown ; the bill black ; the rictus coral- 

 red ; the interior of the mcuth deep pink ; the f set, toes, and claws black. 

 The immature example differed only in having the feet and toes dark 

 brown. 



This species has the upperparts soft gray, slightly tinged brownish 

 on the head ; the upper tail coverts and the greater portion of the outer 

 rectrices white ; the central tail feathers largely black ; a black mark 

 from the base of the bill to around the front part of the eye ; the chin 

 whitish; the throat pale buff, changing to soft gray on the upper 

 breast, which color in turn fades to white on the remaining underparts ; 

 a white bar across the middle of the open wing ; the under wing coverts 

 and axillaries black. 



This is a much smaller bird than the preceding form. The wings 

 are similarly long, but the tail is only slightly forked. 



Family LARIDAE 



CHLIDONIAS HYBRIDA SWINHOEI (Mathews) 



Chinese Whiskered Tern 



Hydrochelidon leucopareia swinhoei Mathews, The birds of Australia, vol. 2, 

 1912, p. 320 (Fuchow, Fukhien, China). 



Delacour and Greenway have recorded (L'Oiseau et la Revue Fran- 

 chise d'Ornithologie, 1940, p. 25) finding terns of this species on the 

 Mae Khong near Ban Huai Sai in December 1938 and January 1939. 

 The bird is not otherwise known from our provinces. 



In nuptial dress this tern has the crown and nape black ; the sides 

 of the head below the eye white; the rest of the plumage gray, palest 

 on the throat and darkest on the abdomen. In nonbreeding dress, it 

 has the forecrown and entire underparts white; the hindcrown and 

 nape blackish, streaked with white. 



From our other terns it is best distinguished by its short, slightly 

 forked tail and its red bill. 



In the absence of suitable material, I can form no opinion on the 

 validity of the various Oriental races of this tern recognized by 

 Mathews. I follow Delacour and Greenway in calling our bird swin- 

 hoei but must point out that it may prove to be inseparable from 

 javanica of Horsfield. 



STERNA AURANTIA J. E. Gray 



Indian River Tern 



Sterna aurantia J. E. Gray, Illustrations of Indian zoology, vol. 1, No. 6, 1830-1832 



[=1831], pi. 69, fig. 2 (no location given=India). 

 Sterna aurantia, Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1936, p. 169 (Chiang 

 Rai). 



