328 STEATIGKAPHICAL GEOLOGY 



The following are some of the most characteristic species of the 

 English and German Permian : 



Bryozoa, Fenestella retiformis, Synocladia virgulacea. 



Brachiopoda. Camaroplioria Schlotheimi, Strophalosia lamellosa, 



St. Goldfussi, Productus horridus, Dielasma elongata, 



Spirifer alatus, Lingula Credneri. 

 Lamellibranchia. Pseudomonotis spehmcaria, Pleurophorus costatus, 



Gervilia (Bakewellia) antiqua, B. ceratophaga, 



Schizodus obscurus, S. Schlotheimi. 

 Gastropoda. Loxonema fasciatum, Natica minima, Pleurotomaria 



antrina, Turbo mancuniensis. 

 Cephalopoda. Temnocheilus Frieslebeni. 

 Pisces. Platysomus striatus, P. gibbosus, Palaeoniscus comptus, 



P. macropomus, Ccelacanthus granulosus, Acrolepis 



Sedgwickii, Rhabdolepis macropterus. 



C. BRITISH PERMIAN ROCKS 



In spite of the fact that the British Permian succession is 

 nowhere complete, and that it is uncertain whether the oldest 

 part of the system is represented, Permian rocks cover considerable 

 areas in England, and it will be convenient to describe them before 

 dealing with those of the continent. The oldest Permian Beds 

 must be those which are most nearly conformable to the Upper 

 Carboniferous, and there can be no doubt that those of the Mid- 

 land counties occupy this position. Those found in Devonshire 

 resemble the Rothliegende of Germany, and may be of the same 

 age ; while there can be no doubt of the Thuringian age of the 

 Magnesian limestones of the north-east of England. We shall 

 therefore take these several areas in the above order. 



1. Midland Area 



Beds which appear to be of Permian age, though no fossils have 

 been found in them, occur in Worcestershire, Staffordshire, and 

 Shropshire, extending as far north as Shifnal, and as far west as 

 Shrewsbury and Alberbury, but not reaching into Denbigh nor 

 into North Staffordshire. The Keele Group of the Upper Coal- 

 measures was formerly regarded as part of them, and so closely are 

 they connected with it, and so little evidence is there of any 

 unconformity, that Mr. Cantrill regards them as an upward 

 continuation of the Coal-measures. 1 He also considers them to be 

 'passage beds into the Permian and Trias, but they cannot bridge 

 the whole interval between British Coal-measures and Trias. If 

 they are Carboniferous they might be of Stephanian age, but until 

 this is proved it is better to regard them as Permian and as a 



