unknown elsewhere--a wonderful fact, considering how widely distributed
sea-shells generally are. Of the forty-three shells found in other
parts of the world, twenty-five inhabit the western coast of America,
and of these eight are distinguishable as varieties; the remaining
eighteen (including one variety) were found by Mr. Cuming in the Low
Archipelago, and some of them also at the Philippines. This fact of
shells from islands in the central parts of the Pacific occurring here,
deserves notice, for not one single sea-shell is known to be common to
the islands of that ocean and to the west coast of America. The space
of open sea running north and south off the west coast, separates two
quite distinct conchological provinces; but at the Galapagos
Archipelago we have a halting-place, where many new forms have been
created, and whither these two great conchological provinces have each
sent up several colonists. The American province has also sent here
representative species; for there is a Galapageian species of
Monoceros, a genus only found on the west coast of America; and there
are Galapageian species of Fissurella and Cancellaria, genera common on
the west coast, but not found (as I am informed by Mr. Cuming) in the
central islands of the Pacific. On the other hand, there are
Galapageian species of Oniscia and Stylifer, genera common to the West
Indies and to the Chinese and Indian seas, but not found either on the
west coast of America or in the central Pacific. I may here add, that
after the comparison by Messrs. Cuming and Hinds of about 2000 shells
from the eastern and western coasts of America, only one single shell
was found in common, namely, the Purpura patula, which inhabits the
West Indies, the coast of Panama, and the Galapagos. We have,
therefore, in this quarter of the world, three great conchological
sea-provinces, quite distinct, though surprisingly near each other,
being separated by long north and south spaces either of land or of
open sea.
I took great pains in collecting the insects, but excepting Tierra del
Fuego, I never saw in this respect so poor a country. Even in the upper
and damp region I procured very few, excepting some minute Diptera and
Hymenoptera, mostly of common mundane forms. As before remarked, the
insects, for a tropical region, are of very small size and dull
colours. Of beetles I collected twenty-five species (excluding a
Dermestes and Corynetes imported, wherever a ship touches); of these,
two belong to the Harpalidae, two to the Hydrophilidae, nine to three
families of the Heteromera, and the remaining twelve to as many
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