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JURASSIC PLANTS FROM THE CLEVELAND HILLS. 



By Rev. George J. Lane, F.G.S. 



Palaeobotanical records afford striking evidence on the 

 study of plant evolution. 



The Permo-carboniferous vegetation reveals a compara- 

 tively homogeneous flora of wide geographical distribution, 

 consisting largely of Lycopods. Calamites and Vascular 

 Cryptogams. 



That the " Cycads," the abundance of which is one of the 

 most conspicuous features of the " Mesozoic Flora." existed 

 in Palaeozoic Ages, there is no conclusive proof. Only limited 

 evidence can be supplied of the occurrence of genera which 

 can be confidently placed in any of the existing families of 

 the Conifers. 



At the close of the Wealden period a second evolutionary 

 wave occurred in the world's vegetation, as shown by the 

 decrease of the Cycads and the emergence of Angiosperms. 



The testimony of the Yorkshire rocks contributes much 

 to our knowledge of the vegetation of the Lower Oolitic 

 period. Since the days of Young, Bird, and Phillips, York- 

 shire has been classical ground for Bajocian plants. 



The comparative absence of records from the Cleveland 

 Hills is, however, a regrettable fact. Our area if persistently 

 worked will, I am fully persuaded from my own personal 

 experience, yield valuable contributions to our knowledge 

 of Bajocian vegetation. To the late Rev. J. Hawell we are 

 deeply indebted for his researches in this particular, but 

 much remains to be done. Our knowledge at present is very 

 circumscribed. Coming into this district in 1904 and re- 



