Plate X. 
Fig, 1a.—Closterium intermedium, Ralfs. Living cell. 
Fig. 1b.—Closterium intermedium, Ralfs. Empty cell, 
Fig. 2a.—Closterium, Ralfsii, Breb. Living cell. 
Fig. 26,—Closterium, Ralfsii, Breb. Empty cell. 
Fig. 3.—Closterium,’ Ralfsii,"Breb, Empty cell. 
