304 THE ZOOLOGIST. 
by a border of snow, marked by the feet. of the old birds, and 
raised at least two inches above the general level (vol. ii., p. 213). 
This circumstance somewhat upsets one’s notions regarding the 
cause of migration, which we have been accustomed to consider 
as dependent chiefly on change of temperature and abundance or 
scarcity of food. In this instance there seemed to be no lack of 
food, for there were plenty of fish in the pools between the floes, 
and the old birds were seen carrying them in their bills. The 
numerous small crustaceans also, which are common on the shores 
of the Arctic Sea, would probably furnish sufficient sustenance to 
the parent birds should fish be unaccessible by reason of the ice. 
At page 210 of the Appendix a coloured plate is given of two 
eggs of the Sanderling, Calidris arenaria, which were found by 
Capt. Feilden in lat. 82° 33’ N., on June 24th, 1876. This nest, 
from which he killed the male bird, was placed on a gravel ridge at 
an altitude of several hundred feet above the sea; and the eggs 
were deposited in a slight depression in the centre of a recumbent 
plant of willow, the lining of the nest consisting of a few withered 
leaves and some of the last year’s catkins. 
The eggs of the Knot, Tringa canutus, he was not so fortunate 
as to obtain, though it breeds in some numbers along the shores of 
Smith Sound and the north coast of Grinnell Land. It must be 
common throughout the Parry Islands during summer, for Sabine 
found it nesting in great numbers on Melville Island. Captain 
Feilden and his companions frequently sought for the nest, but 
without success. However, on July 30th, 1876, the day before they 
broke out of their winter-quarters, where they had been frozen-in 
eleven months, an old Knot with three nestlings were found on 
the border of a small lake, not far from the ship. A description of 
the plumage of these nestlings is given on page 212. 
On June 2lst, the first nest with eggs of the Brent Goose was 
discovered in lat. 82° 33’ N., and subsequently many were found 
(vol. ii., p. 216). 
Ten species of fishes were collected between lat. 78° and 83°N., 
and were submitted for determination to Dr. Giinther. Of these, 
two proved to belong to species hitherto undescribed, and have 
been named by Dr. Giinther Salmo arcturus and Salino Naresii. 
The former, a species of Charr, is the northernmost salmonoid at 
present known. It comes nearest to the Charr of Killin (Inverness- 
shire), but differs from it in having a more slender body, rather 
