INTRODUCTION. 
BrrorE proceeding to deal in detail with 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 paleobotanists, 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, 
Charophyta, Bryophyta and Pteridophyta, 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 
1 Geol. Mem. Sussex, p. 9. 
2 H. B. Woodward, Geol. England and Wales, 1887, p. 336. 
b 
