INTRODUCTION. X X XI 



This list, largely taken from Ward, is, as Berry indicates, not 

 entirely to be relied on. 



Jukes-Browne (1911, p. 306), in a general consideration of 

 the deposits, expresses the view that the plants and animals 

 of the Wealden and the Lower Greensand are the same. 



In 1912 Stopes published a detailed and illustrated account 

 of the anatomy of the three Lower Greensand Angiosperms, 

 Aptiana radiata, Wobumia porosa, and Sabidla Scottii. In 

 1913, in the previous volume of this Catalogue, are included 

 some Alga3 from the Lower Greensand. In the present volume, 

 not onty arc many new species of Lower Greensand plants 

 described, but the anatomical details of some of the known 

 species are given for the first time as, for instance, in the case 

 of Pinostrobus susseviensis. 



GEOLOGICAL POSITJON OF THE BRITISH LOWER GREENSAND. 



With one very doubtful exception, all the plants of the 

 Lower Greensand found in the British Isles are from tho 

 South-east of England. The principal localities are the coasts 

 of the Isle of Wight, the quarries of North Kent in the neigh- 

 bourhood of Maidstone and Ightham, in Bedfordshire near 

 Woburn and Potton, and in Buckinghamshire near Lcighton 

 Buz/ard. 



The position of the British Lower Greensand in relation to 

 the other Cretaceous rocks will be seen in the following table, 

 which is taken from Jukes-Browne (1911): 



British British France and 



Northern Area. Southern Area. Switzerland. 



8. (Wanting.) (Wanting.) Daniau. 



7. Upper Chalk. Upper Chalk. Senonian. 



G. Middle Chalk. Middle Chalk. Turonian. 



f>. Lower Chalk. Lower Chalk. Cenomanian. 



4. fled Chalk. Selbomian. Albian. 



.H ( 3. ~j Uppei\ YECTIAN(LO\VEK GKEENSAXD). Aptian. 



2 \ 2. (Lower. Barremian. 



53 Clay. Wealden. 



"~ 1 



o ^ ! Neocomian. 



The British Aptian (for the name Vcctian has never been 

 gencrallj* adopted for the Lower Greensand) consists of thick 

 series of marine beds, chiefly sands and sandstones with 



