164 Evolution and Distribution of Fishes 



The second stratigraphic type is greatly the thickest 

 and most typical, being made up very largely of red sand- 

 stones and conglomerates, at times interbedded with marls, 

 shales, and coal beds, more rarely with marine beds 

 like (a) above. In the fine sandstones, shales, and shaly 

 coals, plant-remains occur that are mostly a curious com- 

 bination of palaeozoic and mesozoic types. Thus species 

 of AsterophyUites, Calamites, Sigillaria, Lepidodendron^ 

 and sphenopterid-neuropterid forms, all surviving from the 

 luxuriant Carboniferous flora, are mixed with Walchia, Bai- 

 era, Foltzia, Glossopteris and Callipteris, that foreshadow 

 mesozoic vegetation. 



Mixed often with these — as at Autun in France — may 

 be crowded layers of phyllopod and other entomostracans, 

 various higher crustaceans, also, according to Fritsch, a 

 macrostomid predecessor of the King Crab, which he 

 named Praelimulus, and which like the eurypterids was 

 thoroughly freshwater; masses of univalve and of bivalve 

 shells; scorpions and insects. These undoubtedly must have 

 been only a few that were more resisting in their outer 

 tissues, compared with many others of softer structure that 

 quickly decayed. 



But vertebrate life was steadily evolving, for while the 

 fishes became Impoverished In individuals and species, am- 

 phibians and even reptiles, became Increasingly abundant 

 and specialized. Details regarding all of these for Europe 

 are given by Fritsch (iig) and Gaudry {124), and in 

 America In the Carnegie Publications already cited. 



The sumptuous volumes of Fritsch furnish the most 

 recent and fullest accounts of European Permian condi- 

 tions, but these pertain to the upper part of the system 

 that has been termed the Zechstein in Germany. The 

 lower beds of the system in that region are treated In detail 

 In Geinitz's work "Die Dyas." But this Lower Permian 

 Is characterized, much as in eastern Pennsylvania, by ex- 

 tensive masses of purple-red rock, and so in Germany Is 

 often known as the "Rothliegende." 



Two Important physical factors seem both to have co- 

 operated In reducing and often obliterating freshwater and 

 land life, during deposit of the Rothliegende or Lower Per- 



