EXPLANATIONS AND REFERENCES, 



PLATE LXI. 



Figures mayninVd f)<M) diameters except Closterium, only 25(1 diameters. 



PAGE. 

 Figs. 1, 2. CLOSTERIUM ACEROSUM, forma striolatum with single and 



twin zygospores, . . 24 



Fig. 3. CLOSTERIUM LINEATUM, Var. costatnm, with twin zygospores, 25 



Figs. 4, 5. ARTHRODESMUS NOTOCHONDRUS, in front and vertical views, 35 



Fig. 6. ARTHRODESMUS INCRASSATUS, V:ir. oyeladatns, . 35 



Figs. 7, 8. COSMARTUM OC^JLIFERUM, front and lateral views, . 30 



Fig. 9-11. PENIUM CRUCIFERUM, in different stages of division 23 



Figs. 12, 13. 'ARTHRODESMUS PACHYCERUS front and lateral views, 36 



" 14,15. ARTHRODESMUS TRIANGULARIS, front and vertical views, 36 



Fig. 16. DormiuM (JEORGK-UM, . 26 



" IT. PENIUM SPIROSTRIOLATUM, var., 22 



" 19. " 23 



" IS. DoclDIUM VERTICILLATUM, 27 



Figs. 20, 21. DoriDiUM RECTUM, 26 



