Mr. H. Seebohm on the Ornithology of Siberia. 343 
and China^ and find that in every case where the large under 
tail-covert has not been shot away this distinction holds good. 
This bird breeds in considerable numbers on the tundra as 
far north as we went. There is a great variation in the 
colours of the eggs in the same nest_, some being much darker 
than others. There are skins of this bird in the Museum at 
St. Petersburg, collected by Baron Maydell in the Tschuski 
Land. 
Anthus richardi, Vieill. 
Richard^s Pipit must breed in great numbers on the exten¬ 
sive meadow-lands which stretch away for miles from Yen-e- 
saisk^ on the banks of the river. I found it common there 
in the middle of August, and shot both adult birds in full 
moult and young in first plumage. This bird has a habit of 
hovering over the ground almost exactly like a Kestrel. 
Anthus trivialis (Linn.). 
1 did not meet with the Tree-Pipit until I reached lat. 62° 
on my return journey. 
-4Motacilla alba, Linn. 
Motacilla alba, Linn. Syst. Nat. i. p. 331 (1766). 
Motacilla dukhunensis, Sykes, P. Z. S. 1832, p. 91. 
Motacilla baicalensis, Swinhoe, P. Z. S. 187L P* 363. 
I think there can be no doubt that M. alba and M. dukhu¬ 
nensis are the same species. The only difierence seems 
to be in the amount of white on the wing-coverts. M. alba 
has dark grey or black wing-coverts, more or less broadly 
edged with white. In M. dukhunensis the inside half of 
each wing-covert is the same as in M. alba ; but the 
outside half is entirely white, making the wing coverts, as 
they lie on the wing overlapping each other, an entirely 
white mass. This latter form seenis to be confined to Siberia 
and India; but as in both these countries a complete series 
of intermediate forms occur also, we cannot consider the 
eastern form more than a variety. The amount of white 
on the wing-coverts of many of the species in this genus, 
and in some of them the amount of white on the secondaries, 
varies so much, that if we were to admit it as a specific cha- 
