50 MESSRS. ROBINSON AND KLOSS ON 



Thalasseus hergii pelecanoides, J., p 143 (Terutau). 



The MalajT'au material in our possession, though hirger than 

 that in tlie hands of Mr. Oberholser, is not sufficient to enable us 

 satisfactorily to discriminate the local races of these sea-terns, our 

 area being apparently the meeting places of three nominal forms, 

 viz , 8. h. crlsfatus, S. b. edtvardsi and 8. h. pelecanoides, but the 

 balance of probability is that the birds on the eastern side of the 

 Peninsula will prove to be >S'. h. cristatufi, while, according to' 

 Oberholser, those from the west should be S. h. edwardsi. We are 

 unable to separate Terutau and Langkawi birds from Tioman and 

 Rhio Island specimens which, fide Oberholser, should be S. h. 

 pelevaiioldes King. 



We have examined nine fully adult birds in fresh breeding 

 plumage from various islands in the Inner Gulf of Siam. Eight 

 males have the wing 334-360 mm. and a female 335, the median 

 beino- 347 mm. On the whole, therefore, we refer all Malayo- 

 Siamese birds to the Australian S. Ij. pelecanoides. 



Sterna media Horsf. 



Sterna media, HorsQeld, Tians. Linn. Soc. xiii, 1821, p. 198 (Java) ; 

 Howard Saunders, Cat. Birds Brit. Mus. xxv, 1896, p. 86. 



This large tern, which is easily recognised by its somewhat 



slender, yellow-orange bill, is sparingly distributed in the Straits of 



Malacca. We have obtained it north of Penang, and there is little 



doubt that it will be found on the coast of west Siam : though it is 



only doubtfully recorded from the Tenasserim coast. It will not, in 



all probabilit}', be found on the eastern side. 



52. Sterna fluviatilis tibetana Saunders. 



Sterna tibetana, Saunders, P. Z. S. 1876, p. 649 (Thibet) ; Hume, 



Stray Feath. viii, 1879, p. 158 (Tongka). 

 Sterna longipennis, Saunders, Cat. Birds Brit. Mus. xxv, 1896, 



p. 60, spms. u., V. 

 SteniK fluviatilis tibetana, J., p. 142 (Terutau). 



Terns of this group are common in the Straits of Malacca, 



and have been referred inditierently to the common European tern 



A. Hume A: DavisDn, Stray Feathers, vi, 1878. E". O. Grant, Fasciculi Malayenses, iii (Birds), 1905, 



B. Mullcr, DieOinis der Iiiscl Salaiiffa, 188-2. F- Holiinson and Kl.^ss, Iliis, 1910-11. 



C. Oiiti •;. liinls lirit. liiirniah, Vols, i Jc ii. 1883. C. (iainlncr. .lomii. N. 11. Sot-. Siam, i, 1015. 



D. Boalioto, I'.Z. S. 1901, Vol. i. H. Kobinsim, Jonrn. F. M, 8. Museums, v, 1915. 



JOUKN. NAT. HIST. SOC. SIAM. 



