OLD CONTINENTS. 581 



Taking all these circumstances into account, the poverty of the ma- 

 rine fauna, the terrestrial lizards, the Amphibia, and the land-plants, I 

 cannot resist the conclusion that the Permian rocks of England were 

 deposited in a lake or in a series of great inland continental lakes, 

 brackish or salt ; and, if this be true, it will equally apply to some 

 other regions of Europe. 



The strata that succeed the Permian formations in the geological 

 scale are those included in the word Trias, on the continent of Europe. 

 These consist of three subdivisions : first and lowest, the Bunter sand- 

 stone ; second, the Muschelkalk; and third, the Keuper marl, or Marnes 

 irisees. The Bunter sandstone on the Continent consists chiefly of red 

 sandstones, with interstratified beds of red marl and thin bands of lime- 

 stone, sometimes magnesian. These form the Grte bigarre of France. 

 In these strata, near Strasbourg, about thirty species of land-plants are 

 known, chiefly ferns, Calamites, Cycads, and Coniferse, and with them 

 remains of fish are found and Labyrinthodont Amphibia. In the same 

 series there occur Lamellibranchiate marine mollusca of the genera 

 Trigonia, Mya, Mytilus, and Posidonia, so few in number that they 

 suggest the idea, not of the sea, but of an inland salt lake, especially 

 when taken in connection with the Labyrinthodont Amphibia and the 

 terrestrial plants. 



The Muschelkalk, next in the series, is essentially marine. A par- 

 tial submergence took place, and a large and varied fauna of Mesozoic 

 type occupied the area previously covered by the lake deposits of the 

 Bunter sandstone. 



Above this comes the Keuper series, with Gypsum and dolomite, 

 land-plants, fish, and Labyrinthodont remains, and a few genera and 

 species of marine shells, again suggesting the idea of a set of condi- 

 tions very different from those that prevailed when the Muschelkalk 

 was formed. 



These strata, as a whole, are the geological equivalents of the New 

 Red Sandstone and Marl of England, with this difference that the 

 Muschelkalk is entirely absent in our country, and we only possess the 

 New Red Sandstone (Bunter) and the New Red Marl (Keuper). 



The kind of arguments already applied to part of the Permian 

 strata may, with equal force, be used in relation to the New Red Sand- 

 stone and Marl of England. I have for long held that our New Red 

 Sandstone was deposited in an inland lake, probably salt, and that our 

 New Red Marl was certainly formed in a salt lake. Pseudo-morphous 

 crystals of salt are common throughout the whole formation, which, 

 besides, contains two great beds of rock-salt, each 80 or 100 feet thick, 

 which could only have been deposited in a lake that had no outflow, 

 and from which all the water poured into it by the rivers of the coun- 

 try was entirely got rid of by evaporation induced by solar heat. It 

 has been proved by analyses that all spring and river waters contain 

 chloride of sodium and other salts in solution, and in such a lake, by 



