PLATE XXXI. 



Figures magnified 5M> <li;i meters. 



1'AfiK 



Figs. 1-3. EUASTRCM PINGUE, front, side and end views, . . llfi 



" 4-6. EIIASTRUM SPINOSUM, three forms, . . . . 116 



Fig. 7. " lateral view. . . .110 



Figs. 8, 9. EUASTRUM ROSTRATUM, . . . . .116 



" 10-15. EUASTRUM ELEGANS, . . . . . 116 



Fig. 16. zygospore, . 116 



" 17. EUASTRUM SPINOSUM, side view of cell. . llfi 

 Figs. 18-22. EUASTRUM INTEGRUM, ..... 117 



" 23, 24. EUASTRUM BINALE, . . . . .117 



" 25, 26. EUASTRUM ELEGANS, . 116 



Fig. 27. EUASTRUM ROSTRATUM, a form of, . . .116 



Figs. 28, 29. EUASTRUM COMPACTUM, . . 117 



" 30,36. EUASTRUM INERME, . . . . .115 



Fig. 31. EUASTRUM OBTUSUM, . . . .117 



" 32. EUASTRUM C-HSPIDATUM, . . . . .115 



Figs. 33-35. EUASTRUM POKORNYANUM, . . 114 



Fig. 36. EUASTRUM INERME, . . . . . .115 



Figs. 37, 38. EUASTRUM CRASSICOI.LE, . . . . . 115 



39-42. EUASTRUM IXSIGNE, 113 



n 



Fig. 43. end view, showing the cruciform apex 



and the quadrate base of the semi-cell, 113 



