INTRODUCTION. xii 
in the present work, we will proceed to a general sketch of 
Wealden paleobotany. 
In the early part of the present century the Wealden series of 
Southern England was examined by Mantell and Fitton, and it 
is mainly to their labours that we owe our earliest knowledge of 
the life of that period. Gideon Mantell in 1822 published a 
work on “The fossils of the South Downs, or Illustrations of 
the Geology of Sussex,” and included those rocks to which the 
term Wealden is now applied under the so-called Greensand 
formations, which he subdivided thus! :— 
Tron Sand. 
Tilgate beds. 
Weald or Oak Tree clay. 
Greensand. 
Greensand formation 
In the first of these subdivisions plant remains are recorded, 
but without any definite names, descriptions, or plates. The first 
figures and scientific names of Wealden plants are those contained 
in a paper contributed to the Transactions of the Geological Society 
in 1824. Two members of the Council, Messrs. Stokes and Webb, 
were appointed to describe certain fossils which had been forwarded 
to the Society by Mantell from Tilgate Forest; in the description 
of the plants ‘invaluable assistance’? was received from Mr. 
Robert Brown. The following species are mentioned, with 
figures*® :— 
Clathraria anomala, 8. and W. Pecopteris reticulata, S. and W. = 
Carpolithus Mantelli, S. and W.= Weichselia Mantelli (Brong.). 
? Hgquisetites Burchardt, Dunk. Endogenites erosa, §S. and W. = 
Hymenopteris psilotoides, S. and W. 
Onychiopsis Mantelli (Brong.). 
In 1883 Mantell’s work appeared on ‘‘The Geology of the 
South-East of England,” and in chapter xi. there is a ‘‘ description 
Tempskya Schimperi, Corda. 
of the organic remains of the Wealden, and particularly of those 
of the strata of Tilgate Forest.”* The specific name of the 
genus Clathraria is changed from anomala to Lyelli, Hymenopteris 
psilotoides is spoken of as Sphenopteris Mantelli, Brong., Pecopteris 
pea 
2 Trans. Geol. Soc. ser. ii. vol. i. 1824, p. 421. 
3p, 232. 
