The Reutelian (at the junction of the Pliocene and Pleistocene), Mafflian and Mesvinian industries, recognised by M. Rutot in Belgium, belong to the doubtful Eolithic Period, not yet generally accepted[41]. The lowest palaeolithic deposit is the Strepyan, so called from Strepy, near Charleroi, typically represented at St Acheul, Amiens, and recognised also in the Thames Valley[42]. The tools exhibit deliberate flaking, and mark the transition between eolithic and palaeolithic work. The associated fauna includes two species of elephant, _E. meridionalis_ and _E. antiquus_, two species of rhinoceros, _R. Etruscus_ and _R. Merckii_, and the hippopotamus. It is possible that the Mauer jaw and the Piltdown skull belong to this stage. The Chellean industry[43], with the typical coarsely flaked almond-shaped implements, occurs abundantly in the South of England and in France, less commonly in Belgium, Germany, Austria-Hungary and Russia, while examples have been recognised in Palestine, Egypt, Somaliland, Cape Colony, Madras and other localities, though outside Europe the date is not always ascertainable and the form is not an absolute criterion[44]. Acheulean types succeed apparently in direct descent but the implements are altogether lighter, sharper, more efficient, and are characterised by finer workmanship and carefully retouched edges. A small finely finished lanceolate implement is typical of the sub-industry or local development at La Micoque (Dordogne). The Chellean industry is associated with a warm climate and the remains of _Elephas antiquus_, _Rhinoceros Merckii_ and hippopotamus. Lower Acheulean shows little variation, but with Upper Acheulean certain animals indicating a colder climate make their appearance, including the mammoth, _Elephas primigenius_, and the woolly rhinoceros, _R. tichorhinus_, but no reindeer.