2. The Magdelenian: named after the cave of La Madeleine in the Dordogne.
3. The Solutrian: after Solutré near Macon.
4. The Aurignacian: after the grotto of Aurignac in the Haute Garonne.
B. Middle Pleistocene (period of the last great extension of glaciers).
1. The Moustierian: so named after the cave of Le Moustier in Dordogne; the epoch of the Neander men. Also called the "epoch of the Mammoth," whilst the upper Pleistocene is called the epoch of the Reindeer, though the Mammoth still survived then in reduced numbers.
C. Lower Pleistocene (inter-glacial and early glacial, also called period of the Hippopotamus and of Elephas antiquus and Rhinoceros Merckii).
1. The Chellian: named after Chelles on the upper Seine, river gravels and sands earlier than the Moustierian. Large tongue-shaped flint implements, flaked on both surfaces—the later and better-finished classed as "Acheulæan," after St. Acheul, near Amiens.
2, 3, 4 ... various fluviatile and lacustrine gravels, sands and clays divisible into separate successive horizons, as well as marine deposits, some of glacial origin—including the mid-glacial gravel, the boulder clays and shelly Red Crag and Norwich Crag (but not the underlying "Coralline" Crag, which must be classed with the Pliocene). The relations of the marine deposits to the older river-gravels and fresh-water deposits, and to the earlier periods of glacial extension indicated by the glacial moraines of central Europe, have not been, as yet, satisfactorily determined.
The amount of the sedimentary deposits of the earth's crust belonging to the Pleistocene or Quaternary Period—about 250 feet in thickness—is exceedingly small, and represents a surprisingly short space of time as compared with that indicated by the vast thickness of underlying deposits. It has nevertheless been possible to study and classify the "horizons" of this latest very short period minutely because the deposits are easily excavated, and having been more recently "laid down" have not suffered so much subsequent breaking up and destruction as have the older strata; and further, because they embed at certain levels and in favourable situations an abundance of well-preserved bones and teeth of animals and the implements and carvings in stone and bone made by man. It is worth while to look at this matter a little more exactly.