At The Time Of Our Visit, The
Females Had Within Their Bodies Numerous, Large, Elongated
Eggs, Which They Lay In Their Burrows:
The inhabitants seek
them for food.
These two species of Amblyrhynchus agree, as I have
already stated, in their general structure, and in many of
their habits. Neither have that rapid movement, so
characteristic of the genera Lacerta and Iguana. They are both
herbivorous, although the kind of vegetation on which they
feed is so very different. Mr. Bell has given the name to the
genus from the shortness of the snout: indeed, the form of
the mouth may almost be compared to that of the tortoise:
one is led to suppose that this is an adaptation to their
herbivorous appetites. It is very interesting thus to find a
well-characterized genus, having its marine and terrestrial
species, belonging to so confined a portion of the world. The
aquatic species is by far the most remarkable, because it is
the only existing lizard which lives on marine vegetable
productions. As I at first observed, these islands are not so
remarkable for the number of the species of reptiles, as for
that of the individuals, when we remember the well-beaten
paths made by the thousands of huge tortoises - the many
turtles - the great warrens of the terrestrial Amblyrhynchus
- and the groups of the marine species basking on the coast-
rocks of every island - we must admit that there is no other
quarter of the world where this Order replaces the herbivorous
mammalia in so extraordinary a manner. The geologist
on hearing this will probably refer back in his mind to the
Secondary epochs, when lizards, some herbivorous, some
carnivorous, and of dimensions comparable only with our
existing whales, swarmed on the land and in the sea. It is,
therefore, worthy of his observation, that this archipelago,
instead of possessing a humid climate and rank vegetation,
cannot be considered otherwise than extremely arid, and, for
an equatorial region, remarkably temperate.
To finish with the zoology: the fifteen kinds of sea-fish
which I procured here are all new species; they belong to
twelve genera, all widely distributed, with the exception of
Prionotus, of which the four previously known species live
on the eastern side of America. Of land-shells I collected
sixteen kinds (and two marked varieties), of which, with the
exception of one Helix found at Tahiti, all are peculiar to
this archipelago: a single fresh-water shell (Paludina) is
common to Tahiti and Van Diemen's Land. Mr. Cuming,
before our voyage procured here ninety species of sea-shells,
and this does not include several species not yet specifically
examined, of Trochus, Turbo, Monodonta, and Nassa. He
has been kind enough to give me the following interesting
results: Of the ninety shells, no less than forty-seven are
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 different families. This
circumstance of insects (and I may add plants), where few in
number, belonging to many different families, is, I believe,
very general. Mr. Waterhouse, who has published [4] an
account of the insects of this archipelago, and to whom I am
indebted for the above details, informs me that there are
several new genera: and that of the genera not new, one
or two are American, and the rest of mundane distribution.
With the exception of a wood-feeding Apate, and of one or
probably two water-beetles from the American continent,
all the species appear to be new.
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