The number of species of Fish described or noticed in the following Part
of the Zoology of the Beagle, amount to 137. It is right to observe
that, judging from Mr. Darwin’s manuscript notes, relating to what he
obtained in this department, this is probably not more than half the
entire number which he collected. Unfortunately a large portion of the
valuable collection sent home by him arrived in this country in too bad
condition for examination, and was necessarily rejected.
The localities visited by Mr. Darwin, and at every one of which more or
fewer species of fish were obtained, were the Cape Verde Islands,—the
coast of Brazil, including the mouth of the Plata, together with several
inland rivers and streams in that district,—the coasts of Patagonia, and
the Santa Cruz river,—Tierra del Fuego and the Falkland Islands,—the
Archipelago of Chiloe,—the coasts of Chile and Peru,—the Galapagos
Archipelago,—Tahiti,—New Zealand, King George’s Sound in Australia,—and,
lastly, the Keeling Islands in the Indian Ocean. The great bulk of the
species, however, are from the coasts, east and west, of South America.
The particular locality assigned to each species respectively in the
following work may be relied upon as correct; pains having been taken by
Mr. Darwin to affix a small ticket of tin, with a number stamped upon
it, to each specimen, and to enter a note immediately in the manuscript
catalogue, having the same number attached. In only three or four
instances these tickets were found wanting, on the arrival of the
collection in this country.
A considerable portion of the species examined and described are new to
science, especially of those collected in South America, and the
adjoining Islands and Archipelagos. The new ones are supposed to amount
to seventy-five at least, constituting more than half the entire number;
and amongst these are apparently seven new genera.
It may be interesting to state more particularly from what localities
the new species principally come, and what proportion they bear to the
_entire_ number brought from each of those localities. Thus from Brazil
_about half_ are considered new;—from Patagonia _at least half_;—from
Tierra del Fuego, the Falkland Islands, and the Galapagos Archipelago,
_all are new_, without exception; and _nearly all_ from Chiloe, and the
coasts of Chile and Peru. Of the species brought from Tahiti, New
Holland, and the Indian Ocean, not above _one-fourth_ are new. This
might have been anticipated from the better knowledge which we have of
the Ichthyology of that quarter of the globe, than of South America.
It is much to be regretted that the portion of the collection which has
been lost to science, was obtained in localities most abounding in
novelties, judging from that portion of it which has been saved. Thus,
not above five or six species will be found noticed in the following
work, from Tierra del Fuego, where Mr. Darwin took especial pains to
collect all he could, and, judging from his manuscript catalogue, he
must probably have obtained between thirty and forty. From the Falkland
Islands again, there have been only saved two out of fifteen or
sixteen,—from the coasts of Chile and Peru, not half the entire number
obtained, and not above half from the coasts of Patagonia.
There is also described not above half the species brought from King
George’s Sound, and the Keeling Islands; but as the Indian and
Australian species, or at least the former, have been more frequently
brought to Europe than the South American, they are less to be regretted
than these last.
It is fortunate that _the whole_ of the species obtained by Mr. Darwin
in the Galapagos Archipelago, amounting to fifteen, have been preserved,
and are described in the following pages.
It may now be useful to mention, to what groups principally—first, the
entire number of described species belong, and, secondly, that portion
of them which are considered new. Both these points will be best judged
of from the following table, in which the whole collection is parcelled
out according to the families.