158 Origin of the British Flora. 
Preglacial (Cromer Forest-bed) :— 
Beeston, Sidestrand, Mundesley, in Norfolk ; Pakefield, 
Corton, in Suffolk. 
POTAMOGETON PECTINATUS, L. 
Neolithic :— 
Cowden Glen, Renfrewshire. 
Late Glacial :— 
Hoxne, Suffolk (bed C). 
Preglacial (Cromer Forest-bed) :— 
Common at most localities—drupes often very large. 
POTAMOGETON FILIFORMIS, Nolte. 
Unknown fossil in Britain. 
Recorded from Gotland in the Dryas, Birch, and Pine 
Zones (Gunnar Andersson). 
RUPPIA MARITIMA, L. 
Interglacial :— 
West Wittering, Sussex; Stone, Hampshire. 
Recorded from the Pine and Oak Zones in Sweden 
(Gunnar Andersson). 
ZANNICHELLIA PALUSTRIS, L. 
Late Glacial :— 
Twickenham, Middlesex. 
Interglacial :— 
Stone, Hampshire; Selsey, Sussex ; Endsleigh Street, 
London; Southelmham, Suffolk; Hoxne, Suffolk (bed E); 
Kilmaurs, Ayrshire. 
