The most convincing proof of an arid climate in the north of France with prevailing high westerly winds is found in the layers of 'loess' which occur on the 'terraces' of the Somme, the Seine, the Rhine, and the Danube. These 'lower loess' layers of Third Interglacial times frequently contain implements of the late Acheulean industry. Thus, at Villejuif, south of Paris, late Acheulean implements are found embedded in drifts of 'loess.' In the valley of the Somme, flints of the middle Acheulean stage are also found in the _loess ancien_ and 'river-drift.' In the _tuf de La Celle-sous-Moret_ the layer of 'loess' immediately overlies the tufa layer containing late Acheulean implements and proofs of a cooler climate. [Illustration: FIG. 87. "The valley of the Vézère, a northern tributary of the Dordogne, cuts through a broad plateau of limestone in which the streams have hollowed out deep beds with vertical sides," favorable to the formation of caverns, grottos, and shelters. "Here the landscape of late Acheulean times bore the same general aspect as at present." Photograph by N. C. Nelson.] Among the most famous of the 'loess' stations of late Acheulean times is that of Achenheim on the upper Rhine, west of Strasburg. Here the 'older loess' contains a typical Acheulean culture. With this prolonged epoch of cooler temperature the hippopotamus and the southern mammoth retreated to the warmer portions of southern Europe, and their remains are no longer found associated with the late Acheulean flints. The more hardy straight-tusked elephant and Merck's rhinoceros still continued in the north, apparently well adapted to sustain a very considerable fall in temperature. FORMS OF LATE ACHEULEAN IMPLEMENTS The coups de poing of the _late Acheulean_ exhibit a great advance upon the Chellean, being fashioned into dagger or lance forms, with all the edges carefully chipped. The ovaloid implements of late Acheulean times are often worked into fine and sharp blades, which may have been used like butcher-knives for dismembering the carcasses of game and for cutting up the pelts, while the fine almond and disc shapes may have been used as scrapers to cut off the tissues of the inner surfaces of the hides, which were finally dressed by the grattoir, or flint planing tool. In brief, the coup de poing reaches its acme of development in late Acheulean times, both in the fineness of flaking and retouching and in its symmetry of form. The use of large flakes of flint and the retouching both of the borders and of the extremities of these flakes shows a constantly improving technique. It is in the thin, flat, triangular blades and in the lance-pointed forms that the coup de poing reaches its culmination; but we still observe the development of the oval or almond-shaped forms and of the flattened discs. The implements of this time reach their greatest perfection in the north of France, where flint is so abundant.