THK 1'KKMIAN SYSTKM 343 



The similarity between this series and the " Magnesian lime- 

 stone " of England will at once be apparent. The layer of copper- 

 bearing shale which overlies the basement beds is only about 2 feet 

 thick, and is the analogue, if not the actual continuation, of our 

 .Marl slate"; it yields similar fish remains (Platysomus gibbosus 

 and Palceoniscus Frieslebeni being common species), with scales of 

 Proterosaurus, and occasionally star -fish and Brachiopods, which 

 clearly indicate the invasion of the area by an outer sea. 



The fossils of the Zechstein are similar to those of the English 

 limestones, many of the species being the same, and the only 

 Cephalopoda being a few species of Orthoceras and Nautilus. Some 

 of the beds are almost entirely composed of Bryozoa, species of 

 Fenestella, Acanthocladia, and Phyllopora, and these beds are called 

 " Bryozoon-reefs " by German geologists, a misleading term suggest- 

 ing reef-formation which does not exist, for they are merely lenticular 

 beds of limestone resulting from local Bryozoon growths, like the 

 crinoidal and coralliferous limestones of Devonian and Silurian age. 



In Hesse the composition of the Thuringian differs little from 

 the above, but north of the Harz district thick beds of gypsum and 

 rock-salt come in, which are worked at Stassfurt, Egeln, Vienenburg, 

 and other places. The rock-salt is sometimes over 1000 feet thick, 

 and at Sperenberg (south of Berlin) it is over 3000. 



The typical Zechstein facies of the Thuringian extends also 

 eastward into Silesia (north of Gatz). 



3. Russia 



In Kussia, as already stated, the Permian is largely marine, but 

 the limestones with marine fossils are often interbedded with sand- 

 stones, shales, and marls of estuarine or lacustrine origin. According 

 to Nikitin, in the typical district of the ancient kingdom of Permia 

 now the provinces of Perm, Samara, and Ufa the series is divisible 

 as follows : 10 



(Red marly sandstone. 

 Red marly limestone. 

 Grey limestones and marly sandstones. 

 v , /Red sandy marls (marine fossils). 



in \ Marly limestone without fossils. 



fClays with gypsum and beds of limestone. 

 Artinskian -j Dolomitic limestones with Permian fossils. 

 [Dolomitic limestones (Penno-Carboniferors). 



The stages were not established when Nikitin wrote, but I have 

 bracketed his subdivisions to show how they probably correspond 

 with the grouping made in the Ural region. 



On the western slopes of the Urals the Fusulina limestone of 

 the Uralian is succeeded by a series of sandstones, limestones, and 



