THE BIRDS OF SOUTH-WEST AND PENINSULAR SIAM- 61 



and to S. longijwnnis Nordtn., a somewhat closely related species 

 breedinir in North China, Kanischatka, etc., and wintering in the 

 south. All the birds found in these waters are, however, either 

 innnature or in wir)ter plnniage, and it is impossible to identify them 

 with any great certainty. 



The balance of probability is in favour of their belonging to 

 the Asiatic race, which breeds in Tibet, etc., and winters iu the south. 

 The bird has not been found on the East Coast of Siani. 

 53. Sterna doug-alli Mont. 



Sterna doiajaUi, Mont., Orn. Diet. Snppl. 1813. fig. (no pagination- 

 Scotlitnd); A., p. 492 (Laynah Creek); H., p 142 (Koh Pemiaii) ; 

 Williamson, Joiirn. Nat. Hist. Soc. Siam, ii, 1916, p. 63 (Koh 

 Rin and Koh Pliai, Inner Gulf of Siam). 



The Roseate Tei-n has been nuich divided and many names 

 are available for eastern and southern races, but we do not here 

 attempt precisely to assign the Siamese specimens to any subspecies. 



Two birds obtained by ourselves on Koh Pennan on 2Gth 

 May, 1913, in freshly moulted full breeding plumage, have the tarsi 

 and toes orange-red, the claws blackish, and the bills entirely black 

 with no trace of red whatever. Wing d , 228 : d', 213 mm. 



On the other hand, three males from Pulau Jemor, Aroa Ids., 



Straits of Malacca, shot on 2nd. August, 1906, also in full breeding 



plumage, have the tarsi, toes and claws orange-red, and the bills also 



orange-red with no trace whatever of black. Wing 6, 214, 217, 



230 mm. 



54 Sterna sumatrana sumatrana Raffles. 



Sterna suinatrana, llaflles, Tnuis. Linn. tSoc. xiii, 1821, p. 329 

 (immature — Sumatra) ; A., p. 493 (Tenasserim). 



Sterna melanauchen, Temminck, PI. Col. 1827 (Coast of Celebes) ; 

 H., pp. 18, 142 (Koh Pennan, Bandon - Bight) ; Williamson, 

 Jonrn. Nat. Hist. Soc. Siam, ii, 19U3, p. (33 (Inner Gulf of 

 Siam). 



This beaultiful tern, which in life has a delicate rosy flush 



over the under surface like in 8. dougdlli, is a species fre(|uenting 



rocky islands and keeping as a rule well out to sea. It is common 



I. Gyldenstolpe, Kuntfl. Sv. Vct^ Akad. Handl. M. Baker, Joum. X. H. Soc. Siam, iii, 1919. 



.56, No. 2, 1916. (first part). 



J. Robinson, Journ. F. M. S. Miis. vii, 1917. Baker, .Tourn. X. II. Soc. Siam, iii, 1919. 



K- Kloss. Ibis, 1918. (second part). 



L. Kobinson and Kloss, .Tourn. X. H. Soc. Siam, M. I. Baker, .Tourn. X. H. S»o. Siam, iv, 1920. 



iii, 1919. (thii-d part). 



VOL. V, NO. 1, 1921. 



