I'LATK LVI. 



l-'isi'iii-rs ma^niried ~><M> diameters. 



PAQB. 



Figs. 1-3. STAURASTRUM ACULEATUM, in three aspects, . . !'>:; 



Fig. 4. STAURASTRUM TELIKKIU'M, normal si/.e, . . 154 



" 5, 6. STAURASTRUM BREBISSONII, . . . . . 1 "">! 



" 7, 8. STAURASTRUM CERBERUS, ... . 156 



" 9, 10. STAURASTRUM TRIDENTIFERUM, . . 15(i 



" 11-13. STAURASTRUM CRUCIATUM, . . 156 



" 14-16. STAURASTRUM HYSTRIX, ..... 156 



" 17,18. STAURASTRUM RAVENELII. (Compare Plate LX I II, figs. 7,8), 157 



Fig. 19. STAURASTRUM HIRSUTUM, ..... Io5 



' 20. " " dividing, . . . loo 



" 21. zvgospore with empty cells attached, loo 



Figs. 22, 23. STAURASTRUM -CHIAUM, .... loo 



" 24,25. STATRASTRUM CONTROVERSUM, . . . 157 



" 26,27. STAURASTRUM SETK^ERUM, . . 154 



Fig. 28. STAURASTRUM VESTITUM, xygospore with remains of cells, . 151 



Figs. 29, 30. " large form, front and end views. 151 



" 31, 32. STAURASTRUM ECHINATUM, front and end views, 1">4 



" 33, 34. STAURASTRUM iSAXONicuM, front and end views, 154 

 " 35, 36. STAURASTRUM PECTEN, front and end views, . . .155 



