84 TRANSACTIONS OF THE [Sess. lxxvi. 



but a step on the way to their complete elucidation. No 

 sharp line can be drawn between two associations, and it is 

 often difficult to determine whether a certain species belongs 

 to one association or to another. 



In the Kenfig sand-dune area the Salix repens association 

 is of a transitional type. In its more open stations on the 

 mobile dunes the majority of its subordinate species are 

 those of the Marram grass association. Towards its inner 

 limit, fixation of the sand is complete, and the included 

 species are those of the fixed dunes. 



Before enumerating the species which are found in the 

 chief associations, it is necessary to call attention to the 

 plants which occupy the foreshore, above high-water mark. 

 These plants are usually included in the sand-dune forma- 

 tion, although, as a rule, they are more of a halophilous 

 nature. This association of strand plants is not well 

 developed on this part of the coast; only a few species 

 occurring here and there. The following are the commoner 

 species : Cakile maritima, Scop. ; Arenaria peploides, 

 Linn.; Salsola Kali, Linn. 



Marram Grass Association. 



In the " flats " and sheltered hollows among the " shifting " 

 dunes the following species occur :— 



DOMINANT SPECIES. 



Ammophila arenaria, Link. 



ABUNDANT SPECIES. 



Erodiurn cicutarium, Euphorbia Paralias, Linn. 



L'Herit. Euphorbia portlandica, 

 Anaphalis margaritacea, B. Linn. 



& H. fil. Iris fcetidissima, Linn. 



Senecio Jacobcea, Linn. Carex arenaria, Linn. 

 Cnicus arvensis, Hoffm. 



FREQUENT OR OCCASIONAL SPECIES. 



Erigeron acre, Linn. Cynoglossum officinale ,Linn. 



Taraxacum erythrosper- Verbascum Thapsus, Linn. 



mum, Andrz. Verbena officinalis. Linn. 



