Page:The Geologist, volume 5.djvu/20

6 term a varied mineral group, which neither in Germany nor elsewhere had then received one collective name adopted by geologists, albeit it was characterized by one typical group only of animal and vegetable remains. As the subdivisions of this group in Germany consisted, in ascending order, of Rothliegende, with its overlying strata of Weissliegende, Kupfer-Schiefer, and Lower and Upper Zechstein, and in England of Lower Red Sandstone and Magnesian Limestone, with other accompanying sands, marls, etc., so well described by Sedgwick, the name of "Permian"—purposely designed to comprehend these various strata—was readily adopted, and has since been generally used. Even Geinitz himself, as well as his associate Gutbier, published a work under the name of the 'Permische System in Sachsen.' Naumann has also used the term in reference to the group in other parts of Saxony; whilst Göppert has clearly shown that the rich Permian Flora is peculiar and characteristic of this supra-carboniferous deposit. In England, France, and America no other term in reference to this group has been used for the last fifteen years.

The chief reason assigned by Geinitz for the substitution of the word "Dyas" is, that in parts of Germany the group is divided into two essential parts only—the Rothliegende below, and the Zechstein above, the latter being separated abruptly from all overlying deposits.

Now, not doubting that this arrangement suits certain localities, I affirm that it is entirely inapplicable to many other tracts. For, in other regions besides Russia, the series of sands, pebbles, marls, gypseous, cupriferous, and calcareous deposits form but one great series. In short, the Permian deposits are for ever varying. Thus, in one district they constitute a Monas only, in others a Dyas, in a third a Trias, and in a fourth a Tetras.

In this way many of the natural sections of the north of Germany differ essentially from those of Saxony; whilst those of Silesia differ still more from each other in their mineral subdivisions, as explained