Plate XII, 
Fig. 1a,—Tetmemorus granulatus, Breb, Living cell. 
Fig. 1c.—Tetmemorus granulatus, Breb. Empty cell. 
Fig. 1d,—Tetmemorus granulatus, Breb. Zygospore. 
Figs, 2a, 2b, 2c, 2¢,—Staurastrum sexangulare, Lund. 
