1870. ] MR. R. SWINHOE ON CHINESE PLOVERS, 139 
lower mandible, and also in some a paleness of the tarse, both of 
which by a little intensifying would produce the results characterizing 
our species. Judging from these, I should consider that it is not 
long since our southern residents separated from their northern 
brethren, and remained behind to colonize the coast of the south. 
If the separation be so recent, it is rather curious that the southern | 
residents receive each winter the visits of their northern brethren 
without inducing any of the latter to abide with them, or without 
being induced themselves to return to the home of their forefathers. 
Want of strength to return to the north may have induced the first 
individuals to settle in the south; and their offspring may naturally 
have preferred to continue in their birthplace, in the warm climate 
they had been reared in. 
For the sake of comparison with the above Chinese bird, I will add 
a notice on a specimen of Aig. nivosa (Cassin), d, from Peru in 
summer dress, from Mr. Harting’s collection. 
Bill in front *65 inch; wing 4; tarse 1. Bill and legs shorter 
and more slender than in 4g. cantianus. Wants the loral black 
streak. Wings shorter. Has a washed-out appearance on the upper 
parts. Crown only tinged with chestnut. Legs paler. From 2g. 
dealbatus it differs in its much smaller bill, and shorter tarse and 
toes—but, like it, seems to be only a climatal race of 42g. cantianus, 
derived probably in a similar way. 
Aigialites niveifrons (Cuv., Less. Tr. d’Ornith. p. 543) of South 
Africa appears to be another analogous derivative of the same main 
species. 
I was at first under the impression that yialites perronit 
(Miiller) of Java was another race of Ag. cantianus. But in this I 
am mistaken. Dr. Schlegel, of Leyden, has kindly supplied me with 
a specimen in the summer and another in the winter plumage, and 
I will here briefly note their peculiarities. 
Charadrius perronii, Miiller, Verhandl. Rather smaller than 
Bg. minor, with a thicker bill, longer tarse, and shorter wing. 
Summer plumage.—Has a narrow black band over the white fore- 
head. The loral streak is black, but does not meet over the bill, nor 
does it stretch under the eye; ear-coverts black. The frontal black 
is not edged posteriorly with white; but there is a white line above 
the ear-coverts. The crown is pale chestnut-brown, as in ig. can- 
tianus, with a broad white nuchal collar, succeeded by a broad black 
band, which retains its breadth to the sides of the breast, but be- 
comes very narrow across the breast. The back and wings are light 
brown tinged with rufous. The greater wing-coverts and secondary 
quills are edged with white; and the shafts of the primaries, with 
the tips of the inner ones, are white. The tail-coverts and the six 
central tail-feathers are blackish brown. The two outer tail-feathers 
are pure white; the third pale brown edged with white. The bill is 
black, with a spot of pale ochreous at the base of the lower mandible. 
The legs look as if they had been pale yellowish brown. 
Length of adult male about 6 inches; wing 3°85; tail 2; bill in 
front °56; tarse 1; middle toe (claw *17) *75. 
