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 intombed, 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 latitude 49 degrees 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 great collection lately brought to Europe from the caves of Brazil by MM.

Lund and Clausen.
In this collection there are extinct species of all the thirty-two genera, excepting four, of the terrestrial quadrupeds now inhabiting the provinces in which the caves occur; and the extinct species are much more numerous than those now living: there are fossil ant-eaters, armadillos, tapirs, peccaries, guanacos, opossums, and numerous South American gnawers and monkeys, and other animals.

This wonderful relationship in the same continent between the dead and the living, will, I do not doubt, hereafter throw more light on the appearance of organic beings on our earth, and their disappearance from it, than any other class of facts.
It is impossible to reflect on the changed state of the American continent without the deepest astonishment.