The Pampas of South America are not less famous in Geology for the remains of Gigantic quadrupeds, than the Lias of England for its colossal marine reptiles. These vast undulating plains, which present to the eye for nine hundred miles a waving sea of grass, consist chiefly of stratified beds of gravel and reddish mud; and it is in these beds that the remains of many unshapely but powerful terrestrial animals have been found embedded. So abundant are they, that it is said a line drawn in any direction through the country would cut through some skeleton or bones. Indeed, Mr. Darwin is of opinion that the whole area of the Pampas is one wide sepulchre of these extinct animals. It will be enough for our purpose to describe one in particular, which, from its prodigious bulk, has received the appropriate name of Megatherium, or the Great Wild Beast. The Megatherium, like the Ichthyosaurus and the Plesiosaurus, had many affinities with the existing creation. In its head and shoulders it resembled the sloth which still browses on the green foliage of the trees in the dense forests of South America; while in its legs and feet it combined the characteristics of the Ant-Eater and the Armadillo. But it was eminently distinguished from these and all the other modern representatives of the family to which it belonged by its colossal proportions. It was often twelve feet long and eight feet high; its fore-feet were a yard in length and twelve inches in breadth, terminating in gigantic claws; its haunches were five feet wide, and its thigh bone was three times as big as that of the largest elephant. “His entire frame,” as Dr. Buckland has admirably observed and carefully demonstrated, “was an apparatus of colossal mechanism, adapted exactly to the work it had to do; strong and ponderous, in proportion as this work was heavy, and calculated to be the vehicle of life and enjoyment to a gigantic race of quadrupeds, which, though they have ceased to be counted among the living inhabitants of our planet, have, in their fossil bones, left behind them imperishable monuments of the consummate skill with which they were constructed,--each limb, and fragment of a limb, forming co-ordinate parts of a well adjusted and perfect whole; and through all their deviations from the form and proportions of the limbs of other quadrupeds, affording fresh proofs of the infinitely varied and inexhaustible contrivances of Creative Wisdom.”