the Chalk. He could not account, however, for the implement fashioned out of ironstone, which is not found in the vicinity of these caves. He had been under the impression that coprolites were of frequent occurrence in the Hyæna-dens. The filling-in of the cavern had doubtless been accelerated by the water overflowing into it from the stream now flowing at the base of the Crags, but which at that period ran at a higher level. There were slight traces of a rearrangement of the bones such as would be effected by water.
Prof. Boyd Dawkins, in reply, stated that he had no intention of generalizing from this single example; but it was worthy of note that here, as in M. Mortillet's classification, the ruder implements were older than the more highly wrought flint flakes. The Hyæna, like other animals, takes refuge in whatever place will best suit him, and round the mouth of his den bones and coprolites accumulate. The absence of coprolites in this cave was probably due to moisture dripping from the roof, which would dissolve and wash them away; the caves in which coprolites are found were probably dry. The evidence of the cave-Hyænas having preyed on large game, such as the Rhinoceros, rests on the fact that the bones of those animals found in the caves show marks indicating that they have been gnawed. A sick or wounded animal, even though of large size, would easily fall a prey to their numbers. The occurrence of the remains of Hyænas as far north in Siberia as the banks of the Lena and Obi was an important fact and new to him. It indicated a difference of climatal conditions in that country of a marked character.
