THE GREY OR SPOT-BILL DUCK. r7t 
170. To judge, therefore, from my few specimens, they are 
shorter and broader than those of the Mallard, and they 
wholly want the peculiar greenish tint of the eggs of that 
species, 
IN THIS SPECIES the males are only slightly larger than the 
females. Both sexes measure as follows :— 
Males.— Length, 23°8 to 25:9; expanse, 34:0 to 38°5; wing, 
106 to 11'2; tail from vent, 4°7 to 5°38; tarsus, 1°84 to 1°93; 
bill from gape, 2°4 to 2°75; weight, 2 lbs. 5 ozs. to 3 lbs. 4 ozs. 
Females—Length, 22'0 to 24'0 ; expanse, 32°5 to 36:0; wing, 
@2-to 10°7,; tail from vent, 4°9.to 5°3; tarsus, I°7 to 1-9 ; bill 
from gape, 2°3 to 2°5 ; weight, 1 lb. 14 ozs. to 2 lbs. 12 ozs, 
The legs and feet in the old adult male are the most intense 
coral to vermilion red ; in the female usually somewhat duller, 
and more of a tile red. In younger birds of both sexes they 
are more orange, sometimes quite orange yellow. The claws 
are black, and there are not unfrequently black or dusky 
spots or patches on the webs; the irides vary from light to 
deep brown ; the bill is black, the base of the upper mandible 
on the forehead, similarly coloured to the feet and varying as 
they do; the terminal one-fourth of the upper mandible, (more 
or less, it varies in different individuals) except the nail, and 
also a patch at the tip of the lower mandible, a very bright 
clear yellow in some, reddish yellow to orange in others. 
In the young birds of botli sexes the brightly coloured 
patches at the base of the upper mandible are either wholly 
wanting or barely indicated, thus recalling the adult of the 
nearly allied A. zouorhyncha of China. 
THE PLATE would have been very fair had the median por- 
tion of the bill been coloured black, and not pale lead colour, 
and had the legs been coloured red as those of perfect adults 
always are, and not orange. The speculum is too duli and 
pale a green; it is really a rich emerald green in most lights, 
a lovely rich blue or purple in others. 
The plumage varies a little;—some birds show much more, 
others less white on the tertials than in our figures ; in some 
specimens the spots on the lower surface are smaller, and the 
ground colour more nearly white; and in some the brown of 
the back is everywhere more of a purple chocolate. 
DUCKS OF the same type, as the Mallard and Grey Duck, 
and belonging to the genus Azas, as commonly restricted in 
modern times, are numerous and occur all over the world. 
