INTRODUCTION 



Befoeb proceeding to deal in detail witli the fossil plants from 

 the "Wealden. rocks of England, it may be useful to summarize 

 the results of previous workers in the field of "Wealden 

 vegetation. After a sketch of the work already published by 

 English geologists and palaeobotanists, we will briefly notice those 

 records of fossil plants from other countries which may serve as 

 data, from which to draw conclusions as to the distribution of 

 such floras as agree more or less closely with that of the English 

 "Wealden. 



The present volume is only concerned with the Thallophyta, 

 CJiarophyta, Bryophyta and Pteridopliyta, but in the lists quoted 

 in the following pages the higher plants are included. In 

 each case the specific names are reproduced unaltered from the 

 writings of the several authors, with the addition of the newer 

 titles in those cases where a change has been proposed in the 

 present Volume. 



ENGLAND. 



The term " Wealden " appears to have been first proposed by 

 P. J. Martin' in 1828, and is a modification of Weald Measures, 

 instituted in 1822 by J. Middleton.^ Martin, in his Geological 



' Geol. Mem. Sussex, p. 9. 



2 H. B. "Woodward, Geol. England and Wales, 1887, p. 356. 



b 



