NEW OR NOTEWORTHY BIRD-RECORDS FROM SIAM. 37 
“58. Hydrochelidon leucoptera (Meisner and Schinz). 
The White-winged Black Tern. 
I have three specimens of a small tern, shot in the neighbour- 
hood of Bangkok, which I have identified as belonging to this species. 
One, obtained in February 1915, is in winter plumage, while the other 
two, which were procured in April and October 1918, appear to be 
immature individuals, so the only means of distinguishing them from 
H. hybrida (the Whiskered Tern), which is the common species in this 
locality, is by size. By this test the identification seems correct, and 
Ican see no difference between my birds and a specimen of H, 
leucoptera, from Penang, which has been kindly sent to me by 
Mr. H. C. Robinson for comparison. 
12. W.214 mm. Bill from gape 35. 
22 imm. W. 200, 206 mm. Bill from gape 52, 34. 
Iris dark brown. Bill blackish brown, slightly tinged with 
red. Gape pale reddish. Mouth reddish flesh. Legs orange-red, 
dusky in front. Claws dark horn. 
*59. Hydroprogne caspia (Pall.). Zhe Caspian Tern. 
I obtained three fine specimens of this large and handsome 
tern at Tachin, Central Siam, in March 1917. They were all shot 
flying over the river, and, as observed by Blanford (Faun. Brit. 
India, Birds, iv (1898), p. 310), this species may be readily dis- 
tinguished (apart from its great size) by its habit, when looking for 
food, of flying over the water with the hill directed downwards, 
almost at right angles to the line of the body. It is usually found 
singly, but sometimes a couple may be observed together. 
2d. W. 408, 405 mm. 
12. W. 400 mm. 
Iris dark brown. Bill sealing-wax red, dusky at tip. Mouth 
sealing-wax red. Legs and claws black. 
60. Sterna sinensis Gmel. The White-shafied Ternlet. 
1¢, 192. Koh Lak, South-western Siam, June 1917. 
2d. Hua Hin, South-western Siam, June 1918. 
Males. T.L. 236, 240, 280 mm. W. 181, 180, 187. 
Female. T.L. 248 mm. W. 186. 
VOL. III, NO. I, 1918. 
