ANNUAL ADDRESS, MDCCCLXXIII. 35 



it. The Permian system is the youngest member of the 

 primary or palaeozoic group, and its fossils are closely akin 

 to those of the carboniferous times. " It forms, " says 

 Professor Ramsay, "a narrow and marked strip on the 

 east of the coal measures from Northumberland to Not- 

 tinghamshire, where it chiefly consists of a long, low, flat- 

 topped terrace of magnesian limestone, interstratified with 

 two or three thin beds of red marl, sometimes containing 

 gypsum. The scarped edge of this limestone, which is 

 sparsely fossiliferous, faces west, and overlooks the lower 

 undulations of the coal measure area. Before the end 

 of this palasozoic epoch, the Permian beds were deposited 

 in great inland salt lakes analogous to the Caspian Sea 

 and other salt lakes in Central Asia at the present day. 

 That area gives the best modern idea of the state of 

 much of the world during Permian times." (Physical 

 Geography and Geology, p. 81.) The limestone of this 

 period in the North consists of two beds, one of thin- 

 bedded grey limestone, 80 feet thick, and the other of 

 magnesian limestone, 500 feet thick. The characteristic 

 fossils consist of about 24 species, according to Professor 

 King, and are comprised in seven families, of which may 

 be mentioned polyzoa, brachiopoda, conchifera, and gastero- 

 poda. The prevailing colour of this limestone is yellowish. 



I have now completed my description of the physical 

 geology of the primary or palasozoic limestones, and come 

 to the mesozoic or secondary, the first of which occurs 

 on the Continent in the Triassic beds, but not here, and 

 is known by the name of muschelkalk, so named from 

 the shells it contains. Its thickness is nearly 600 feet. 



The next formation is one in which limestone plays an 

 important part. It is called the Jurassic or Oolitic 



