SUCCESSION OF STRATA. 189 



5. THE OOLITE. This is a marine formation of vast extent 

 and thickness, its name means egg stone, because, it is formed 

 of small egg like grains. It consists of limestones and clays, 

 which abound in marine shells, corals, fishes; reptiles, both ter- 

 restrial and marine; land plants of peculiar species, and the re- 

 mains of two or more genera of marsupial animals, are likewise 

 found in it. 



6. THE LIAS. This name is supposed to be a provincial cor- 

 ruption of the word layers, as it consists of shale, or indurated 

 slaty clay, which splits into layers, alternating with clays and 

 limestones, containing marine shells, cephalapoda, crinoidea and 

 fishes. It is chiefly remarkable however, for its remains of 

 enormous reptiles particularly the plesiosaurus and the ichthyos- 

 aurus. The Lias group consists of the upper lias shale, mixed 

 with the lower oolite, containing saurian remains, belemnites and 

 ammonites ; the lias marls; calcareous, sandy, and ferruginous; 

 the lower lias clay and shales intercalated with sands and sep- 

 taria, and lastly a series of laminated limestones, with partings of 

 clay, which change into vast beds of red marl and sandstone 

 forming, 



7. THE SALIFEROUS, OR NEW RED SANDSTONE SYSTEM. A 

 marine formation comprising variegated marls and sandstones, 

 and conglomerates, frequently of a red color. The name new is 

 given to distinguish it from a formation of the same mineralogical 

 character but much older.- This series of deposits is remarkable 

 for the traces or footsteps of marsupial animals and birds, and 

 contains fossil remains of marine and terrestrial plants, fishes and 

 reptiles. This series forms the grand depository of rock-salt and 

 Jime, hence called the saliferous, salt bearing. Its variegated 

 color is owing to oxide of iron. The series consists of the upper 

 new red sandstone, containing gypsum and rock salt, with varie- 

 gated red and white sandstones, conglomerates or detritus qf 

 older rocks cemented together, and the lower new red sandstone, 



Consisting of magnesian limestones called dolomite, and marls 

 and conglomerates colored with oxide of iron. This series rests 

 upon, 



i* 



