20 Messrs. Robinson and Kloss on Birds from the 
Asarcornis leucoptera (Blyth) ; Oates, Man. Game Birds 
Ind. pt. ii. p. 136 et seqq. (1899) ; Robinson, Jonrn. Fed. 
Malay States, iv. p. 132 (1910). 
This Duck was very abundant in Trang, from various 
districts in which State we have obtained over a dozen 
specimens. 
At Chong near the foot of the main dividing-range, which 
was the only locality in which we personally met with the 
species, it was fairly numerous and used to come down to 
the partially flooded rice-fields to feed in the early morning 
and late afternoon. For so heavy and solid a bird it was a 
very powerful flier and capable of carrying oft a large 
dose of lead. In the evening, after feeding, it went off to 
roost in the patches of jungle growing on small and steep 
hills rising from the general level of the rice-fields. The 
specimens that we ourselves examined had been feeding 
on very large snails, apparently a species of Ampullaria , 
with which their crops were crammed. 
The changes of plumage are very puzzling in this species, 
and we are rather doubtful whether the sexes really differ 
in any material particular, save the slightly larger size of 
the male. 
Of the eight specimens now before us, four are almost 
uniform glossy black below and have the mantle and back 
also black, the former glossed with metallic green. The 
black wing-speculum beneath the white shoulder is broad 
and clearly defined, and the bills are bright yellow blotched 
with fuscous. 
Three of these specimens are sexed male and are un¬ 
doubtedly adult. They have the bony knobs at the angle of 
the wing well developed. A fourth is sexed female by the 
collector, but cannot be in any way distinguished from the 
other three specimens. 
A fifth bird has the under surface brown, a black collar 
round the fore-neck, and the upper surface dull oily brown, 
some glossy green feathers are, however, appearing. The 
speculum on the wing is ill-defined and the knuckle¬ 
dusters ” not very pronounced ; bill paler than in the others 
and more heavily blotched. Wing 14*2 inches. 
