100 A. S. Green — The Permian Beds of S. Yorkshire. 



saturation would at length be brought about, and precipitation would 

 take place, and Dr. Sterry Hunt has shown that dolomite and gypsum 

 would be the probable products. 



Such a state of things would be by no means favourable to animal 

 life ; few creatures could exist at all under such circumstances, and 

 the few that did manage to live on would show by their dwarfed 

 and stunted forms how trying were the conditions against which they 

 had struggled. Professor Eamsay pointed out that this was just the 

 character of the Magnesian Limestone fauna, that the species were 

 few and the individuals puny, and he showed how in this respect it 

 agTced exactly with the fauna of recent inland seas, such as the 

 Caspian and the sea of Aral. 



The paper dealt with broad, general views, and did not pretend 

 to enter into details. On reading again, however, the paper of Mr. 

 Kirkby on the Permians of South Yorkshire,^ the palseontological 

 minutiae, so admirably worked out therein, seemed to me to confirm 

 in a remarkable way Prof. Eamsay's theory ; and I think it is worth 

 while to call attention to them, especially as I do not know that their 

 bearing in this direction has been noticed before. 



The Permian beds of South Yorkshire fall into the following sub- 

 divisions : — 



6. Upper Marls and Sandstones with Gypsum. 



5. Upper Limestone or Brotherton beds. 



4, Middle Marls and Sandstones with Gypsum, 



3. Small grained Dolomite. 



2. Lower Limestone. 



1. Quicksands. 



Certain red beds below the quicksands, which were supposed by 

 Prof. Sedgwick and other geologists to represent the Eothliegendes, 

 -are omitted here, because there is every reason to believe that they 

 are nothing more than Carboniferous rocks stained by infiltration.'^ 



No. 1. Pure unconsolidated sand, mostly finely grained, but occa- 

 sionally containing small quartz pebbles ; excessively current-bedded ; 

 very irregular in its occurrence. No sign of passage into the over- 

 lying limestone. 



Loose sandy beds are found in places beneath the Lower Lime- 

 stone, which are nothing more than the sandy residue of the limestone 

 itself, the calcareous matter having been carried away by percolating 

 water. Such beds, however, are totally distinct from the quicksands, 

 and can be easily distinguished from them. 



No. 2. Dolomitic limestone containing a large quantity of sand. 

 Mr. Kirkby describes 31 species of fossils from this division. The 

 mollusca are for the most part stunted, but some, notably Axinus 

 diibius, are robust and abundant in individuals. 



No. 3. Dolomite far purer and freer from mechanical admixture 

 than the bed below : often crystalline or sub-crystalline. No fossils 

 except a few traces in the lowest beds. 



No. 5. Flaggy limestone, sparingly or not at all dolomitic, with 

 thin way-boards and beds of red, purple, and green marls. Of the 



^ Quart. Journ. Geol. Soc. of London, vol. xvii., p. 287. 



^ See a paper by Mr. J. C. "Ward, Quart. Journ. Geol. Soc., 1869, vol. xxv., p. 291. 



