The ravine in which it was discovered, in 1852, is one of the many which pierce the dolomitic conglomerate, or petrified sea-beach, of the Triassic age, resting at the foot of the cliffs from which it was torn by the waves, and overlying the lower slopes of the Mendips (see Fig. 1). Open to the south, it runs almost horizontally into the mountain-side, until closed abruptly northwards by a perpendicular wall of rock, 200 feet or more in height, ivy-covered, and affording a dwelling-place to innumerable jackdaws. Out of a cave at its base, in which Dr. Buckland discovered pottery and human teeth, flows the river Axe, in a canal cut in the rock. In cutting this passage, that the water might be conveyed to a large paper-mill close by, the mouth of the hyæna-den was intersected in 1852, and from that time up to December 1859 it was undisturbed save by rabbits and badgers, and even they did not penetrate far into the interior, or make deep burrows. Close to the mouth of the cave the workmen (employed in making this canal) found more than 300 Roman coins, among which were those of Allectus and of Commodus. When the Rev. J. Williamson and myself began our exploration, about twelve feet of the entrance of the cave had been cut away, and large quantities of the earth, stones, and animal remains had been used in the formation of an embankment for the stream which runs past the present entrance of the cave. According to the testimony of the workmen, the bones and teeth formed a layer about twelve inches in thickness, which rested immediately upon the conglomerate-floor, while they were comparatively scarce in the overlying mass of stones and red earth. The workmen state also that at the time of the discovery of the cave the hillside presented no concavity to mark its presence. So completely was the cave filled with débris up to the very roof, that we were compelled to cut our way into it. Of the stones scattered irregularly through the matrix of red earth, some were angular, others water-worn; all are derived from the decomposition of the dolomitic conglomerate in which the cave is hollowed. Near the entrance, and at a depth of five feet from the roof, were three layers of peroxide of manganese, full of bony splinters, and, passing obliquely up towards the southern side of the cave and over a ledge of rock that rises abruptly from the floor: further inwards they became interblended one with another, and at a distance of fifteen feet from the entrance were barely visible. In and between these the animal remains were found in the greatest abundance. [Illustration: FIG. 83.--Plan of Hyæna-den at Wookey Hole. Right lines = sections; dotted areas = bone-beds; shaded areas = ashes and implements.]