Mr. H. Seebohm on the Ornithology of Siberia. 185 
developed. JL. lahtora, Sykes, is probably entirely confined 
to India, where it breeds—though L. lewcopygius, Hempr. apud 
Severtz., from Turkestan, may prove to be this species. The 
skin from the Amoor in the Swinhoe collection, which Sharpe 
and Dresser incorrectly identified with ZL. lahtora, Sykes, 
appears to me to be L. homeyeri, Cab., originally described 
(loc. cit.) from South Russia. Hence it passes eastwards 
through Turkestan, where it has been described by Severtzoff as 
L. leucopterus (Ibis, 1876, p. 184), to Central Siberia, whence 
Mr. Kibort has sent me two skins obtained by him at Kras- 
no-yarsk’ on the 18th of May and the 12th of August. ast- 
wards it appears to be found near Lake Baical (Tacz. Journ. 
f. Orn. 1874, p. 322) and onthe Amoor. In this species, as in 
L. lahtora, Sykes, the secondaries are not only tipped with 
white, but are always white on the basal half of both webs, 
and some of them are always white on the entire inside web. 
A third species having this peculiarity appears to be L. deal- 
batus, Defil., from Algeria, Tunis, and Sennaar (fide skins in 
the British Museum). This species appears to be mterme- 
diate in the colour of the upper parts between JL. lahtora, 
’ Sykes, and L. homeyeri, Cab., differing also from the former 
in wanting the narrow black frontal line of feathers, and 
from the latter in its smaller size and distinct geographical 
range. 
Lantus magsor, Pall. 
My immature bird from the Amoor is undistinguishable 
from L. borealis, Vieill.; but I have seen an almost complete 
series from it to LZ. excubitor, Linn. That the amount of 
white at the base of both webs of the secondaries is not a 
question of age, appears to me to be sufficiently proved by 
the skin of a nestling from Baden in Dresser’s collection, in 
which the white on the secondaries is as much developed as 
in typical skins of fully adult L. excubiior, Linn. The only 
explanation that I can suggest is that L. excubitor, Linn., is 
the western form, which in Europe may be said to be almost 
pure-bred. Iv Asia it would appear to interbreed along the 
whole line with L. borealis, Vieill., which becomes the pre- 
SER. IV.—VOL. IV. 0 
