MESOZOIC AND TERTIARY FLORAS 



109 



The flora of the Jurassic, while in the main a continuation of that 

 of the late Trias, and consisting of equisetums, ferns, cycads, ginkgos, 

 and conifers, shows the incoming of a number of more modern types 

 in these groups. The cycads were of course abundant and diversified, 

 whence it has been called the age of cycads. The flora is remarkably 

 uniform over wide portions of the world. Thus not far from 50 per 

 cent, of the North American flora — exclusive of the cycad trunks — 

 is the same as that found in Japan, Manchuria, Siberia, Spitzbergen, 

 Scandinavia, or England, and what is even more remarkable, the 

 plants found in Louis Philippe Land, 63° S., are practically the same 

 as those from Yorkshire, England. 



