Overlying this whole series of old (or palæozoic) rocks, which are inclined to the north, is a horizontal, and therefore unconformable capping of _new red sandstone_. This also is from near Bristol, and the quantity provided was fifty tons. The new red sandstone, thus capping the old rock on the high ground of the plateau, re-appears at the extremity of the nearest of the adjacent islands at a much lower level, and having a different mechanical position. It is right to mention that these geological sketches are the result of careful consideration, and have not been effected without much constructive ingenuity. The original plan of the whole was suggested by Professor Ansted, and arranged with Sir Joseph Paxton at an early period of the laying out of the grounds; and as soon as the state of affairs permitted and the actual earthworks of the Plateau were in progress, a model of the intended structure was completed and coloured geologically by Professor Ansted. The works have been ably constructed from this model by Mr. James Campbell, who also procured the stone and other minerals from different parts of the country. [Illustration: The Labyrinthodons.] Let us now return to the Plateau, from whence we can obtain the best view of the islands and their singular tenants. Before describing them, however, we will remind the visitor that the lowest or oldest rocks, which we have shown him, were the old red sandstone; next above them were the carboniferous limestone, the millstone grit, the coal-measures, and then the new red sandstone. It is with this last formation that the restorations of the extinct animals commence. Before that period fossil remains indicate that fish inhabited the waters of the earth, but there are no traces of the existence of any reptiles or higher animals. Reptiles first appear in the new red sandstone, and as the extreme right of the islands is arranged to represent this formation, it is there that we shall find the Labyrinthodon and the Dicynodon, of each of which there are two species. The strata which overlie the new red sandstone will be now mentioned in the order of their super-position, each successive formation bringing us nearer to the forms of animal life which are at present living upon the earth.