feet; and of this, only relics are left in the form of flat
gravel-capped hills. The upper plain of Santa Cruz slopes up to a
height of 3000 feet at the foot of the Cordillera. I have said that
within the period of existing sea-shells, Patagonia has been upraised
300 to 400 feet: I may add, that within the period when icebergs
transported boulders over the upper plain of Santa Cruz, the elevation
has been at least 1500 feet. Nor has Patagonia been affected only by
upward movements: the extinct tertiary shells from Port St. Julian and
Santa Cruz cannot have lived, according to Professor E. Forbes, in a
greater depth of water than from 40 to 250 feet; but they are now
covered with sea-deposited strata from 800 to 1000 feet in thickness:
hence the bed of the sea, on which these shells once lived, must have
sunk downwards several hundred feet, to allow of the accumulation of
the superincumbent strata. What a history of geological changes does
the simply-constructed coast of Patagonia reveal!
At Port St. Julian, [12] in some red mud capping the gravel on the
90-feet plain, I found half the skeleton of the Macrauchenia
Patachonica, a remarkable quadruped, full as large as a camel. It
belongs to the same division of the Pachydermata with the rhinoceros,
tapir, and palaeotherium; but in the structure of the bones of its long
neck it shows a clear relation to the camel, or rather to the guanaco
and llama. From recent sea-shells being found on two of the higher
step-formed plains, which must have been modelled and upraised before
the mud was deposited in which the Macrauchenia was entombed, it is
certain that this curious quadruped lived long after the sea was
inhabited by its present shells. I was at first much surprised how a
large quadruped could so lately have subsisted, in lat. 49 degs. 15',
on these wretched gravel plains, with their stunted vegetation; but the
relationship of the Macrauchenia to the Guanaco, now an inhabitant of
the most sterile parts, partly explains this difficulty.
The relationship, though distant, between the Macrauchenia and the
Guanaco, between the Toxodon and the Capybara,--the closer relationship
between the many extinct Edentata and the living sloths, ant-eaters,
and armadillos, now so eminently characteristic of South American
zoology,--and the still closer relationship between the fossil and
living species of Ctenomys and Hydrochaerus, are most interesting
facts. This relationship is shown wonderfully--as wonderfully as
between the fossil and extinct Marsupial animals of Australia--by the
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