des Sc. Anth., p. 807) the tranchet is to be found in great numbers in the plateau stations of the departments of the Aube, Calvados, Nièvre, Oise, Saône-et-Loire, Yonne and others. The industrial remains of these stations scarcely advanced to the degree of using the polished stone axes, which are sparingly met with.
Of the less known of the early haunts of man during the transition period, one of the most instructive is a series of shell-mounds, discovered in 1863, in the valley of the Tagus, near the villages of Salvaterra and Mugem. The mounds are grouped on the left bank of the Tagus at from twenty-five to thirty metres above sea-level, and distant some thirty miles from the maritime shores of the present embouchure of the river. The shells are of marine origin, and when they were gathered and used as food, it is supposed that the sea extended up the valley as far as the shell-mounds which suggests that the land must have since risen considerably. The industrial remains disclosed by excavations are of a very rude character, consisting of primitive implements made of flint, quartzite, bone and horn. Among the flints are a few knife flakes, and some small cutting implements of rhomboidal forms. There are also some large flat stones, used for grinding purposes, together with the small hand rubbers. Horn and bone were utilized as chisels, pointers, spatulæ, etc. No polished axes, nor pottery, nor any indications of domestic animals have been found in these Portuguese settlements.
