straits. Trawling was besides carried
on three times in the twenty-four hours, commonly with an
extraordinarily abundant yield, among other things of large shells,
as, for instance, the beautiful _Fusus deformis_, Reeve, with its
twist to the left, and some large species of crabs. One of the
latter (_Chionoecetes opilio_, Kroeyer) the dredge sometimes brought
up in hundreds. We cooked and ate them and found them excellent,
though not very rich in flesh. The taste was somewhat sooty.

Lieutenant Bove constructed the diagram reproduced at page 244,
which is based on the soundings and other observations made during
the passage, from which we see how shallow is the sound which in the
northernmost part of the Pacific separates the Old World from the
New. An elevation of the land less than that which has taken place
since the glacial period at the well-known Chapel Hills at Uddevalla
would evidently be sufficient to unite the two worlds with each
other by a broad bridge, and a corresponding depression would have
been enough to separate them if, as is probable, they were at one
time continuous. The diagram shows besides that the deepest channel
is quite close to the coast of the Chukch Peninsula, and that that
channel contains a mass of cold water, which is separated by a ridge
from the warmer water on the American side.

[Illustration: SHELL FROM BEHRING'S STRAITS. _Fusus deformis_, Reeve. ]

If we examine a map of Siberia we shall find, as I have already
pointed out, that its coasts at most places are straight, and are
thus neither indented with deep fjords surrounded with high
mountains like the west coast of Norway, nor protected by an
archipelago of islands like the greater part of the coasts of
Scandinavia and Finland. Certain parts of the Chukch Peninsula,
especially its south-eastern portion, form the only exception to
this rule. Several small fjords here cut into the coasts, which
consist of stratified granitic rocks, and in the offing two large
and several small rocky islands form an archipelago, separated from
the mainland by the deep Senjavin Sound. The wish to give our
naturalists an opportunity of once more prosecuting their
examination of the natural history of the Chukch Peninsula, and the
desire to study one of the few parts of the Siberian coast which in
all probability were formerly covered with inland ice, led me to
choose this place for the second anchorage of the _Vega_ on the
Asiatic side south of B