Of twenty-one species of post-glacial mammals identified in the deposits of Brixham Cavern, only four are regarded as extinct species, and these include the _ursus spelæus_ and _hyæna spelæa_. But their habitats have been widely changed in the climatic and geographical revolutions which have intervened. Some have to be sought for within the Arctic circle; others in low latitudes, and on continents lying wholly outside of that world which was alone known to Aristotle and Pliny. Every thing indicates a revolution slowly wrought through unnumbered ages, during which the ancient fauna was being supplanted by novel species, including those which belong to the historical period of temperate Europe. So far as appears from present evidence, man himself has to be included among the new additions to the European fauna. To this post-glacial period must, at any rate, be assigned the advent of the Flint-Folk of the Drift: a race of hunters and fishers not greatly differing in their rude arts from the more immediate precursors of the Historic races in Europe’s Stone Age; but who were contemporaneous with the Siberian mammoth and other extinct elephants, the woolly rhinoceros, the musk-ox, and the reindeer of France; and with numerous extinct carnivora of proportions corresponding to the gigantic herbivora on which they preyed. The regions in which remains of the Flint-Folk have hitherto chiefly occurred embrace the valleys of Northern France and Southern England, where now the vine and the hop clothe the sunny slopes with their luxuriance. But as fresh evidence accumulates, corresponding indications are found to extend to the shores and islands of the Mediterranean. Traces of Europe’s neolithic artificers have been found in the caves of Gibraltar; and among a singularly interesting accumulation of flint-flakes, polished stone axes, rude pottery, etc., lying beside the skeletons of their owners, in the same caves of Andalusia from one of which a golden tiara of primitive workmanship has been recovered.[9] Among remoter traces in the Maccagnone, Sicilian cave, Dr. Falconer could discover nothing suggestive of a different period for the rude flint implements and the numerous bones of the hippopotamus, mammoth, cave-lion, and other fossil mammals with which they were conjoined; while far eastward, near Beyrout, the Rev. H. B. Tristram reports the occurrence, in the stalagmitic flooring of a limestone cave, of bones and teeth assigned to a fossil ox, the red-deer, and the reindeer, alongside of the flint-knives or flakes which the prehistoric cave-men of Lebanon had used when feasting on such prey.[10] But though such traces occur on ancient historic sites, we search in vain for any connecting link between the oldest historic races and those belonging to an era which one distinguished geologist has designated as “The Second Elephantine Period”;[11] when, according to his reconstruction of the physical geography of the region, the Thames was a tributary of the