INTRODUCTION 



FOR the first time the Flora of the Lower Greensand (Aptian 

 age) of Britain is considered as a unit. Hitherto the fossils 

 which represent it have been dismissed as insignificant, and, 

 Avith the exception of Bennettites Qibsonianus and Ciipressin- 

 oxylon vectense, their anatomy has remained undescribed. In 

 addition to the two plants just named, a few gymnospermic 

 cones and undetermined '* woods " are all that have been noticed. 

 It is not surprising, therefore, that one of the most recent 

 references to the Lower Greensand vegetation should state 

 this general impression as follows : " The land of Vectian 

 [i. e. Lower Greensand] time was doubtless similar in aspect 

 and climate to that of Wealden time, and the plants and 

 creatures which inhabited the country were the same " (Jukes- 

 Browne, 1911, p. 306). 



In reality, the flora of the English Lower Greensand is rich, 

 not only in species, but in interest, and it offers a startling 

 contrast to the flora of the preceding Wealden. Furthermore, 

 while the fossils which represent the Lower Greensand flora 

 have generally been neglected as poorly preserved and frag- 

 mentary, the actual fact is that petrifactions of the internal 

 anatomy of this age are surprisingly excellent, and the micro- 

 scopic details of many of the Lower Greensand species are 

 not surpassed by the most beautiful of the Coal - Measure 

 petrifactions. 



The plants of the Lower Greensand in this country are found 

 under very favourable conditions : occurring in a well-defined 

 and well-known marine deposit, their exact geological position 

 is clear. Had this not been the case, there must have been 

 much doubt regarding the age of the flora, for it is so unlike 

 any other previously known. 



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