THE BIRDS OF NORTHERN THAILAND 111 



My examples had the irides red or bright brown ; the frontal plate 

 ivory white or pinkish yellowish, edged white; the interior of the 

 mouth fleshy white ; the bill fleshy white or horny white, pinkish at 

 the base of the culmen ; the exposed portion of the tibiae wholly light 

 orange, wholly bright olive-green, or orange behind and olive-green in 

 front ; the tarsi brown-olive or dull olive-green ; the toes olive-green, 

 duller or darker at the joints; the lobes of the toes olive-green, slaty 

 below and at the edges above ; the claws blackish slate. 



The adult has the head and neck dull black ; the entire upperparts 

 blackish slate; the entire underparts slaty gray; the under tail coverts 

 dull black. The immature is browner and has the underparts more 

 or less mottled with white. 



The coot is a swimming bird that occurs at the same places as the 

 gallinule, from which it may at once be known by its larger size and 

 its white, not red, bill and frontal plate. It is the only Thai rail hav- 

 ing the phalanges of the toes edged with membranous lobes. 



Family HELIORNITHIDAE 



HELIOPAIS PERSONATA (G. R. Gray) 



Masked Finfoot 



Podica per sonata G. R. Gray, Proc. Zool. Soc. London, 1848 [=1849], p. 90, Aves, 



pi. 4 (Malacca). 

 Heliopais personata, Vijjakich, Journ. Siam Soc. Nat. Hist. Suppl., 1934, p. 330 



("about fifteen miles [north of Lainpang] along the Lampang-Chiengrai 



road"). 



The only northern record for the rare finfoot is the adult female 

 taken by Vijjakich and deposited in the collection of Cornell Univer- 

 sity. The collector has published the date as November 11, 1930, but 

 on the specimen label the date appears as "11.2.30." The species is 

 perhaps only a straggler to our provinces. 



Vijjakich states that his bird was swimming and was probably 

 searching for food. An extralimital example, which I took at Tha 

 Chalaep, near Chanthaburi, May 4, 1937, was found on mud flats 

 among mangroves at low tide and had been feeding upon small crabs 

 and mollusks. 



My specimen had the irides brown ; the eye ring yellow-green ; the 

 bill bright yellow, with the basal two-thirds of the culmen horny 

 brown ; the feet and toes green ; the lobes of the toes greenish yellow ; 

 the claws horn. 



The adult male has the forehead and sides of the crown, the sides 

 of the head, the throat, and entire f oreneck black, the last parts edged 

 by a narrow white line beginning behind the eye; the remainder of 



