INTKODTTCIIOir. Xlll 



in the present work, we will proceed to a general sketch of 

 Wealden palseobotany. 



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' : — 



Ilron Sand. 

 Tilgate beds. 

 Weald or Oak Tree clay. 

 Greensand. 



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 Eorest ; in the description 



of the plants " invaluable assistance " was received from Mr. 



Eobert Brown. The following species are mentioned, with 



figures^ : — 



Pecopteris reticulata^ S. and "W. 



Weiehselia Mantelli (Brong.). 

 JEndonenites erosa, S. and "W. 



Tempslcya Schimperi, Corda. 



Clathraria anomala, S. and W. 

 Carpolithus Mantelli, S. and W. - 



? Equisetites Burehardt, Dunk. 

 Symenopteris psilotoides, S. and "W". = 



Onychiopsis Mantelli (Brong.). 



In 1833 Mantell's work appeared on "The Geology of the 

 South-East of England," and in chapter xi. there is a " description 

 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, Symenopteris 

 psilotoides is spoken of as SpJienopteris Mantelli, Brong., Pecopteris 



1 p. 22. 



2 Trans. Geol. Soc. ser. ii. vol. i. 1824, p. 421. 

 = p. 232. 



