PLATE 20 



Prasiola delicata S. and G. 



Pig. 1. A micro-photograph of a marginal segment, surface view showing 

 the arrangement of the vegetative cells. X 442. 



Prasiola Tneridion-alis S. and G. 



Fig. 2. A micro-photograph of a portion of the surface, showing vegetative 

 cells and interspersed aplanospores (?). X 442. 



This plate is from Setchell and Gardner, Phyc. Cont. I, 1920, pp. 279-324, 

 pi. 25. 



[348] 



