Other methods of classification have been suggested, but as they are more or less modifications of that of Mortillet, generally arising out of variations in the archaeological materials in different countries, such as that adopted by M. A. Rutot of Brussels (Congrès de Dinant), they require no further notice.
As all these so-called epochs are mere halting-points on the high road of man's advancing civilisation, it is often difficult to determine to which epoch relics from intermediate stations are to be assigned.
Chelléen.
The alluvial gravels at Chelles form a small plateau about; 8 miles east of Paris, 48 metres above the sea, and 8 metres above the bed of the Marne, from which it is 2 kilometres distant. A section shows three separate layers, within a thickness of 8 metres, resting on Tertiary deposits. The lowest layer is especially interesting, on account of the number of teeth of Elephas antiquus and meridionalis (Fig. 11) which it has yielded, associated with remains of Hippopotamus major, Rhinoceros merckii, Trogonthérium, cave-bear, and cave-hyæna, together with flint implements almost exclusively of the coup-de-poing type. These animals were survivals from the Pliocene Age, and the presence of their bones in any locality indicates a warm climate. The middle portion of the deposits was cemented by calcareous infiltrations, and both it and the upper sandy gravels were later formations, and contained only bones of the mammoth and flint implements of Moustérien types. Mortillet regarded the relics of the lowest bed as the oldest evidence of the existence of man in France, outside the so-called Eolithic flints of the Tertiary period; and hence he took it as the most typical station in his classification of the Palæolithic industry instead of Saint Acheul. There is not, however, much difference between the oldest flints of the two stations. Those of the latter have a greater variety of forms, and the coup-de-poing is sensibly thinner, smaller, and more delicately chipped at the edges. The more pointed of the Chelléen types are known to the workmen as "ficrons," while the almond-shaped specimens, called "limandes," are characteristic Acheuléen forms (Pl. III.) Moreover, the two earlier elephants E. antiquus and E. meridionalis, and Rhinoceros
