THE BROWN SEAWEEDS OF THE SALT MARSH. 335 
Blackwater Fucus, though they are not identical, the Clew Bay plant being 
more richly branched, slightly tougher, and of a more reddish-brown colour 
than the Blackwater plant. 
The evidence, however, points strongly to the inclusion of these dwarf 
varieties also under Fucus vesiculosus. 
Fre. 6,— Fucus vesiculosus megecad limicola ecad volubilis. д nat. size. 
Large form with vesicles and receptacles. Ray Marshes, Blackwater, Essex. 
The British Marsh Fuci in general. 
These four localities may be taken as fairly typical of the Fucus vegetation 
of British salt marshes. The most common form under which the Fucus 
appears is the small turf-like form known as F. balticus, Ag., or sometimes 
described as F. vesiculosus v. subecostata, after Harvey. This occurs in 
many marshes, as, for example, in the marshes behind Mochras in Carnarvon, 
or in the marshes of the Aln, Northumberland, as an undergrowth with a 
short turf of Glyceria, Armeria, ete. The specimens in the herbaria at Kew 
and the British Museum, from different parts of the country, approach in 
