former Distribution of British Plants. 157 
Late Glacial :— 
Hoxne, Suffolk (bed C); Ballaugh, Isle of Man (bed D), 
Interglacial :— 
Endsleigh Street, London; Hitchin, Hertfordshire ; 
Southelmham, Suffolk. 
Preglacial (Cromer Forest-bed) :— 
Beeston, Sidestrand, Trimingham, Mundesley, in Norfolk. 
POTOMAGETON DENSUS, L. 
Interglacial :-— 
West Wittering, Sussex. 
POTAMOGETON OBTUSIFOLIUS, Mert. & Koch. 
Interglacial :— 
Endsleigh Street, London; Southelmham, Suffolk. 
POTAMOGETON PUSILLUS, L. 
Neolithic :— 
Hailes, near Edinburgh; Redhall, near Edinburgh ; 
Cowden Glen, Renfrewshire. 
Late Glacial :— 
Hoxne, Suffolk (bed C). 
Interglacial :— 
Hoxne, Suffolk (bed D). 
POTAMOGETON TRICHOIDES, Cham. 
Late Glacial :— 
Hoxne, Suffolk (bed C). 
Interglacial :-— 
West Wittering, Sussex; Stone, Hampshire; Southelm- 
ham, Suffolk; Hoxne, Suffolk (beds D and E). 
