PLATE XXIV. 



FIGS. PAGE 



1-5. Closterium lineatum Ehrenb. 1, x 200 (after 



Ralf s) ; 2, x 400 ; 3, x 520 ; 4, zygospore, 



x 120 ; 5^ portion of cell-wall of conjugating 



specimen, x 520 . . .181 



6-7. CL Ralfsii Breb. 6, x 300 ; 7, x 200 (after 



Ralfs) . . .182 



8-13. CL Ralfsii var. hybridum Rabenh. 8, 10, and 

 11, x 520; 9, x 220; 12, zygospore, x 120; 

 13, portion of cell-wall of conjugating speci- 

 men, x 520 . 183 



