Besides the hyena and the bear, more than a hundred species of extinct animals have been discovered in our ossiferous caves. In those of Paviland, Glamorganshire, bones of a primeval elephant have been found; and in that of Wirksworth, Derbyshire, the almost entire skeleton of a rhinoceros lay buried in a considerable mass of gravel and osseous fragments. How the large creature came there is a question that may well exercise the ingenuity of a geologist. Though in these and similar cases, the bone-caves have been found to contain the remains of animals very different from those now existing in the same region, yet in general they show a remarkable relationship, in the same land or continent, between the dead and the living. Thus in the caves of Brazil 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, such as fossil ant-eaters, armadilloes, tapirs, peccaries, guanacoes, opossums, and numerous South American gnawers, monkeys and other animals. [Illustration: CAVE IN DREAM LEAD MINE, NEAR WIRKSWORTH, DERBYSHIRE.] The kangaroo, as is well-known, is peculiar to Australia, and caverns in that country have been described by Sir T. Mitchell, containing fossil bones of a large extinct kangaroo. A singular wingless bird, the Apteryx australis, is found only in the wilds of the interior of New Zealand, where it takes refuge in the clefts of rocks, hollow trees, or in deep holes which it excavates in the ground. The caves of that country show us that it was preceded by other wingless birds of a gigantic structure—the Moas, by the side of which even the ostriches of the present day would shrink into comparative insignificance. These wonderful creatures would probably have remained unknown to the present day, if, in 1839, the thigh-bone of a Moa had not fallen by chance into the hands of Professor Owen, who from this single fragment drew up a surprisingly correct notice of the bird. This memoir, sent out to New Zealand, gave a stimulus to further researches, and from the larger quantity of the Moa’s bones now sent to England, Professor Owen built up the beautiful skeleton which, along with those of the Mylodon robustus, of the Mammoth, and of the primeval stag, forms one of the most conspicuous ornaments of the splendid Museum in Lincoln’s Inn Fields.