n 82 deg. 2'
N.L. The two nests that Malmgren found consisted of depressions,
twenty-three to twenty-six centimetres in diameter, in a heap of
loose gravel, on a ledge of a steeply-sloping limestone-rock wall.
In each nest was found only one egg, which, on the 30th July,
already contained a down-covered young bird. For all the ivory gulls
which have their home on Spitzbergen there were doubtless required
several hundred such breeding-places as that at Murchison Bay. When
to this is added the fact that we never in autumn saw on Spitzbergen
any full-grown young of this kind of gull, I assume that its proper
breeding-place must be found farther north, on the shores of some
still unknown Polar land, perhaps continually surrounded by ice. It
deserves to be mentioned with reference to this, that Murchison Bay
was covered with ice when Malmgren found the nests referred to
above.

Besides these varieties of the gull, two other species have been
found, though very rarely, in the Polar regions, viz., _Larus
Sabinii_, Sabine, and _Larus Rossii_, Richards. Although I have
myself only seen the latter, and that but once (on the Chukchi
Peninsula), I here give drawings of them both for the use of future
Polar explorers. They are perhaps, if they be properly observed, not
so rare as is commonly supposed.

Often during summer in the Arctic regions one hears a penetrating
shriek in the air. When one inquires into the reason of this, it is
found to proceed from a kittiwake, more rarely from a glaucous gull,
eagerly pursued by a bird as large as a crow, dark-brown, with white
breast and long tail-feathers. It is _labben_, the common skua
(_Lestris parasitica_, L.), known by the Norwegian walrus-hunters
under the name of _tjufjo_, derived from the bird's cry, "_I-o
i-o_," and its shameless thief-nature. When the "tjufjo" sees a
kittiwake or a glaucous gull fly off with a shrimp, a fish, or a
piece of blubber, it instantly attacks it. It flies with great
swiftness backwards and forwards around its victim, striking it with
its bill, until the attacked bird either drops what it has caught,
which is then immediately snapped up by the skua, or else settles
down upon the surface of the water, where it is protected against
attack. The skua besides eats eggs of other birds, especially of
eiders and geese. If the eggs are left but for a few moments
unprotected in the nest, it is immediately to the front and shows
itself so voracious that it is n