PLATE XXXI. 



Figures magnified 500 diameters. 



Page 



Figs. 1-3. EuASTRUM PINQDE, front, side and end views, . .116 



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



Fig. 7. " " lateral view, . . . .116 



Figs. 8, 9. EtJASTRUM ROSTRATUM, . . . . 116 



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



Fig. 16. " " zygospore, .. . . . 116 



" 17. EuASTRUM SPINOSUM, side view nf cell, . . 116 



Figs. 18-22. EuASTRUM integrdm, . 117 



" 23, 24. EtJASTRUM BINALE, ... . 117 



" 25, 26. EOASTRDM 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 CUSPIDATUM, . . . . 115 



Figs. 33-35. EuASTRUM Pokornyanum, 114 



Fig. 36. EUA.STRUM INERME, . . . . .115 



Figs. 37, 38. EuASTRUM crassicolle, . . . 115 



" 39-42. EuASTRUM INSIGNE, . . . .113 



Fig. 43. " " end view, showing the cruciform apex 



and the quadrate base of the semi-cell, 113 



