PLATE VII. 



Figure> magnified 2.'>u diameters. 



Park. 

 Closterium DEI ORUM, ...... 43 



ClOBTERIUM SUBTILE, . . . .158 



( LOSTERITJM LREOLATUM, ..... \'-> 



" end. more highly magnified, . 43 



Closterium .Iinmim, . . . . . .44 



Closterium Venus, ;i group of three . . . .44 



" 7. < i.ii-i iimim parvulum, (a group of three), . . . 15 



Figs. 8, 9. ( losterium Dianae, Var. areuatum, and typical form, . 11 



Fig. in. losterium Ralfsii, one half-cell vegetative state, the other 



half lifeless, .... 46 



Figs. 11, 12. Closterium ututum, and zygospo . . . H 



" 13,14. * [iOSTEBIUM Lkiiu.kimi. . . . . , 4(i 



Fig. 15. Closterium moniliferum, . .... 45 



1H. I i ..-i l i:li M I'.llKI n 1:1 l.'.ll. . . . .4-) 



17. Var, imnnn.ru . . 15 



i^. ( i.u-i kkiim acuminatum, smaller form, . . .44 



i; ( longer form, empty cells attached to 



z\ gospi Hi. . . .44 



-u\, Closterii h Leibleinti, zygospore, itli emptj membrane "I 



the copulated cells, . . .46 



