| _Interglacial_ =2= | Strépyan | ? | Palaeoliths of | | = Mindel-Riss interval | Mesvinian | |"ancient-valley" | | (Penck) | Mafflean | | type. | | | | | ?Flood-gravels. | | | | | Valleys do not | | | | | correspond to | | | | | modern river | | | | | | | =Glacial II= | -- | ? | Chalky | | "Mindelian" of Penck | | | Boulder-clay | | | | | | | _Interglacial_ =1= | -- | ? | Brandon beds | | = Günz-Mindel interval | | | with implements | | (Penck) | | | | | | | | | | =Glacial I= "Günzian" | -- | ? | Cromer Till. | | of Penck | | | Later than | | | | | Forest-Bed | +------------------------+--------------+------------+-----------------+ [1] Penck postulates four glaciations, all "pleistocene." [2] Boule recognises two pleistocene glaciations (seemingly Nos. III and IV of Penck), and one pliocene glaciation. The latter is not indicated in the Table. [3] Skertchley's scheme is now ignored, if not abandoned, by the best authorities. It has been introduced here on account of its historical interest only. Its correlation with the other schemes is speculative. [4] The differences between the rival schemes of Boule, Penck and Hoernes are best realised by comparing the position assigned to the Solutréan industry by each in turn. The löss and its divisions are not indicated in this Table. [Illustration: Fig. 25. Chart of the oscillations of the snow-level in Central Europe during the Pleistocene period. (From Penck.) In the uppermost space. _N_ Neolithic Age. _Ma_ Magdalenian. _Sol_ Solutréan. _Günz_, _Mindel_, _Riss_, _Würm_, denote the several glacial phases. This chart is to be read from right to left; on the extreme right the snow-line is first shewn 300 m. above its present level. Then it falls to nearly 1200 m. below the present level, the fall corresponding to the Günzian glaciation. After this it nearly attains its former level, but does not quite reach the line marked + 300. This chart represents the part marked Glacial Epoch in Fig. 24, with which it should be compared.]