J. 8. Newberry—Fossil Plants from Northern China. 127 
Asia. And yet, in the interval between the deposition of the 
Coal-measures and the Triassic rocks the whole flora of the 
globe was revolutionized. Before the Bunter was laid down 
Lepidodendron, Sigillaria, Annularia, Sphenophyllum, Cordaites, 
and indeed all the characteristic forms of the coal flora had dis- 
able to report the facts with a good degree of fulness; but the 
Causes which inspired the revolutions ai have taken place in 
plant life, and the processes by which these great changes have 
been effected seem to be as inscrutable as ever. 
