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Rh of maximum glaciation. The early Palæolithic nomads appeared to have confined their wanderings to the river valleys, living on fruits, roots and the smaller animals.

Although some of the Pleistocene fauna, including the mammoth, reindeer and Irish elk, found their way into Ireland, no evidence of the presence of Palæolithic man in that island has yet been discovered. This may be accounted for by alterations in the relative level of sea and land. The Irish Channel being thirty-eight fathoms deep, while that between England and the Continent is only twenty fathoms, it would follow that the former would become sea, during a process of gradual submergence, long before the latter. When the British Isles stood at their maximum elevation continental mammals could roam as far as the Atlantic without any water impediment, but as the gradual submergence progressed the Irish Channel would be first blocked against them; so that for a considerable interval of time immigrants could still come to Britain but not to Ireland. A similar result would follow on the occurrence of an elevation of land after a state of submergence. From researches carried on some time ago in the cave of Balynamintra, County Waterford, it has been shown that the Irish elk was contemporary with Neolithic man in that neighbourhood.

In 1883 parts of a human skeleton were discovered, while excavating the Tilbury Dock, in a sandy stratum, at a depth of