Plate VIII. 
Fig. 1a.—Closterium striolatum, Zhr. Living cell. 
Fig. 1b.—Closterium striolatum, Zhr. Empty cell, 
Fig. 1d.—Closterium striolatum, Ehr. Zygospore- 
Fig. 2a.—Closterium cornu, Ehr. Living cell. 
Fig. 2b.—Closterium cornu, Zhr. Empty cell. 
Fig. 32,—Staurastram orbiculare, Ralfs. Living frond. 
Figs. 30, 3c.—Staurastrum orbieulare, Ralfs. Empty fronds. 
Figs. 3d, 3¢, 3f—Staurastrum orbiculare, Ralfs. End views. 
Fig. 3g.—Staurastrum orbiculare, Ralfs. Zygospore. 
