Scrobicularia

All the plants have a high northern range, and one, the dwarf Arctic birch, is never found at sea level in latitudes as far south as the Dogger Bank, except very rarely in the Baltic provinces of Germany.

The plants already found are Ranunculus lingua, Castalia alba, Cochlearia species, Lychnis flos-cuculi, Arenaria trinervia, Spiraea ulmaria, Rubus fructicosus, Epilobium species, Galium species, Valeriana officinalis, Menyanthes trifoliata, Lycopus europaeus, Atriplex patula, Betula alba, Betula nana, Corylus avellana, Salix repens, Salix aurita, Sparganium simplex, Alisma plantago, Potamogeton natans, Rupia rostrata, Scorpus species, Carex species, Phragmitis communis.

Among the nine species of beetle determined by Mr. G.C. Champion, it is noticeable that two belong to sandy places.

This suggests that the fen may have had its seaward edge protected by a belt of sand dunes, just as the coast of Holland is at the present day.