pants of the region during the same period. If, indeed, as appears to be in some valleys the case, the unworn implements occur only in the high-level deposits, while in the lower they are either absent or in a much worn condition, the inference is, that in those particular valleys the occupation by man, though for some time contemporaneous with that of the mammoth and his congeners, ceased before the extinction or emigration of the old fauna. In some cases, however, as at Fisherton,[1] the worked flints have been found below the remains of mammoth; while in the beds at Menchecourt, near Abbeville,[2] in which the implements occur, were found the bones of a hind leg of rhinoceros still in their natural position, so that they must have retained their ligaments when deposited, and could not since have been disturbed. With regard to the amelioration of climatal conditions which led to the cessation of the excavation of the valleys, it may not impossibly have been connected with the insulation of the country, when the isthmus connecting it with the continent was cut through by the sea. But this is hardly the place for such speculations. If, however, we may regard the estuarine deposits at Selsey, in which almost entire skeletons of mammoth occur, as belonging to the period when the deposit of the low-level gravels was ceasing, it would appear from the associated molluscan forms, as interpreted by Mr. Godwin-Austen, that the temperature of the waters of the English Channel was at that time such as may now be met with twelve degrees farther south.
If there was a difference in the climatal conditions of the high and low-level deposits, it might have produced some effect on the method of living, and on the implements of the men of the two periods. At one time I thought it probable that a marked distinction might eventually be drawn between the high- and low-level implements, but so far as Britain is concerned, this can hardly be done. Still the facies of a collection from two different spots is rarely quite the same, and I think there is generally a preponderance of the ruder pointed implements in the high-level gravels, and of the flat ovate sharp-rimmed implements in the low-level. In the valley of the Somme, the broad polygonal flakes are certainly most abundant in the lower beds, as at Montiers, near Amiens.
I would, however, deprecate the introduction of such terms as
