PLATE 18 



Fig. 1. Part of the margin or a tuft, established on the epidermis of Postelsia, 

 X 480 diam. 



Fig. 2. Endophytic part of small tuft (dotted), X 480 diam. 



Fig. 3. Endophytic part of small tuft, X 480 diam. 



Fig. 4. .? Pylaiella Postelsiae, basal stratum (dotted) with young erect fila- 

 ments, scratched off from a stem of Postelsia and seen from lower surface, X 480 

 diam. 



Fig. 5. Fragment of the base of a dense tuft, X 240 diam. 



[162] 



