58 



Origin of the British Flora. 



of Oak-roots in place, indicating a soil above the reach of 

 the sea. It lies 35 feet below mean tide level, and points 

 to a subsidence of fully 55 feet. The plants are: — 



Crataegus Oxyacantha. 

 Cornus sanguinea. 

 Corylus Avellana. 



Quercus Robur. 

 Salix Caprea. 

 Sparganium. 



The whole of the deposits belong in all probability to 

 the Neolithic Period. 



Beeston, Norfolk. 



(Reid, 'Piocene Deposits of Britain,' Mem. Geol. Savvey. 

 1890; Reid, 'Geology of the Country around Cromer,' 

 Mem. Geol. Survey. 1882.) 



Two distinct plant-bearing deposits are represented at 

 Beeston. The lower is a peaty loam full of seeds of 

 Temperate plants, and belongs to the Preglacial Cromer 

 Forest-bed. The upper, and newer, is an Early Glacial 

 stratified loam with leaves of Arctic plants, at the base of 

 the Boulder Clays. At one spot an intermediate deposit 

 is perhaps represented ; this is here classed as the base 

 of the Arctic bed. 



Plants from the Cromer Forest-bed : — 



Thalictrum flavum. 

 Ranunculus aquatilis. 



repens. 



Nuphar luteum. 

 Stellaria aquatica. 

 Poterium officinale. 

 Hippuris vulgaris. 

 CEnanthe Phellandrium. 

 Carduus. 



Stachys palustris. 

 Atriplex patula. 

 Rumex Acetosella. 



maritimus. 



Betula alba. 



Alnus glutinosa. 

 Ceratophyllum demersum. 

 Stratiotes aloides. 

 Alisma Plantago. 

 Potamogeton pectinatus. 



trichoides. 



heterophyllus. 



Najas marina. 

 Scirpus paucifiorus (?). 



caespitosus. 



fluitans (?). 



Carex (several sp.j. 

 Isoetes lacustris. 



