ts of the
structure of the Toxodon!

The remains of these nine great quadrupeds and many detached bones
were found embedded on the beach, within the space of about 200
yards square. It is a remarkable circumstance that so many
different species should be found together; and it proves how
numerous in kind the ancient inhabitants of this country must have
been. At the distance of about thirty miles from Punta Alta, in a
cliff of red earth, I found several fragments of bones, some of
large size. Among them were the teeth of a gnawer, equalling in
size and closely resembling those of the Capybara, whose habits
have been described; and therefore, probably, an aquatic animal.
There was also part of the head of a Ctenomys; the species being
different from the Tucutuco, but with a close general resemblance.
The red earth, like that of the Pampas, in which these remains were
embedded, contains, according to Professor Ehrenberg, eight
fresh-water and one salt-water infusorial animalcule; therefore,
probably, it was an estuary deposit.

The remains at Punta Alta were embedded in stratified gravel and
reddish mud, just such as the sea might now wash up on a shallow
bank. They were associated with twenty-three species of shells, of
which thirteen are recent and four others very closely related to
recent forms. (5/1. Since this was written, M. Alcide d'Orbigny has
examined these shells, and pronounces them all to be recent.) From
the bones of the Scelidotherium, including even the kneecap, being
entombed in their proper relative positions, and from the osseous
armour of the great armadillo-like animal being so well preserved,
together with the bones of one of its legs, we may feel assured
that these remains were fresh and united by their ligaments, when
deposited in the gravel together with the shells. (5/2. M. Aug.
Bravard has described, in a Spanish work "Observaciones Geologicas"
1857, this district, and he believes that the bones of the extinct
mammals were washed out of the underlying Pampean deposit, and
subsequently became embedded with the still existing shells; but I
am not convinced by his remarks. M. Bravard believes that the whole
enormous Pampean deposit is a sub-aerial formation, like
sand-dunes: this seems to me to be an untenable doctrine.) Hence we
have good evidence that the above enumerated gigantic quadrupeds,
more different from those of the present day than the oldest of the
tertiary quadrupeds of Europe, li