THE BIRDS OF SOUTH-WEST AND PENINSULAR SIAM. 



47 



fBill imu:li cj 

 I Bill iioniial 



LARIDAE 

 Gulls and Tkkxh. 

 impressed, knife-like 



(Upper mandible longer than the lower 

 1 Mandibles of equal length 



[Pluniage dark above and below : outermost tail feather 



-, not the longest 



(plumage not dark below : outermost tail feather the longest 



Jilti/iickops (extra limital). 

 . . Lanes brunciccplialus. 



. f Tarsus long, exceeding middle toe and claw 

 (Tarsus short, less than middle toe and claw 



e I Bill very stout, tail less than 1/3 the wing . . 

 (Bill normal, tail 1/2 the wing or more 



„ (Tail almost square, the feathers rounded 

 JTail forked, the feathers pointed 



/Larger, bill blood-red in breeding plumage : tail grey in 

 J ! non-breeding plumage 



1 Smaller, bill dull red in breeding plumage : tail white in 

 \ non-breeding plumage 



„ /Tail long, exceeding 3/4 the wing 

 iTail shorter, less than 2/3 the wing 



q f Mantle and back sooty brown 

 \ Mantle and back grey 



(Large, wing over 11.5 inches 

 10 Medium, wing not more than 11 inches 

 (Small, wing less than 8 mches 



J. (Larger, bill greenish 



\ Smaller, bill orange or yellow . . 



,„ (Whole crown always white 



I Crown black or partially black . . 



, ., ( Feet blackish 

 \ Feet reddish 



14 



(Inner webs of primaries edged with white to the tips : 

 ' bill red : feet brighter 



j Inner webs of primaries not edged with white to the tips : 

 ( bill black : feet duller 



( Shafts of all primaries white 

 15 - Shafts of two outer primaries brown 

 I Shafts of three outer primaries brown 



Anoua atulidus. 

 Gelochelidon miglica. 

 Hijdro2)rng}ic cas2)ia. 



Hi/droclielidon hybrida. 



H. Icucoplcra. 



Seena secna. 



Sterna anacthcta. 



S. berrjii pelecanoides. 

 i>. media. 



S. stwiatrajia. 



S. Ivntj'qjennis. 



. . S. dvugalli. 

 S. fliiviatilis tlbetaim. 



. . S. sbiensis. 



. . S. viinuta. 



S. sattndersi. 



10 



12 

 15 

 11 



13 



14 



Note. In this Order we Imvc not, as a rule, atteini)tcd to attach rigorousli/ correct 

 subspecific names to the various forms. This is almost imjMssible wiOwut com- 

 parative material from all jiarts of the Oriental and Australasian regions, ichich 

 is not in our possession. 



!• Gyldenstolix;, Kungl. Sv. Vet. Akiul. llanill. 

 56, No. '2, 1916. 

 J> Robinson, .Journ. V. M. S. Mus. vii, 1917 

 K. Kloss. lbi.s. 1918. 



U. Robinson and Kloss, Journ. X. H. S<x;. Hiam, 



iii, 1919. 



IM. 



Baker, Journ. N. H. Soc. Siam, iii, 1919. 



(first part). 

 Baker. Journ N.H. Soc. Siam. iii, 1919. 



(second part). 

 M.I. Baker, Journ. X.H. Soc. Siam. iv, 19'20. 



(third paft). 



VOL. Y, NO. 1, 1921. 



