PLATE V. A Common Tree Lichen (Pliyscia stellaris) 



A, habit sketch ; /?, diagram of a section through a sac fruit (ascocarp), showing 

 the fruiting surface and layer of algal cells: (7, section showing a group of 

 algal cells (Plenrococciifi), held in the network of fungal filaments: D. section 

 of the fruiting surface, showing sacs (asci) in stages of development among 

 the sterile filaments (paraphyses) 



