PLATE LII. 



Figures magnified 500 diameters. 



Page. 



Fig. 1. Staubastrum quaDbangulabe, a Minnesota variety, . 160 



" 2. " " a Pennsylvania and New 



Jersey variety, . . 160 



Figs. 3, 4. " " end view of Florida forms, 160 



'• 5, 6. Staobastrum crenatum, . ... 138 



Fig. 7. Staurastbdm longispinum, . . . 160 



Figs 8, 9, Staubastrum spinosum. See St. fwcalum and Kitchdii, . 152 



" 10, 11. Staubastrum pulchrum,* .... 147 



" 12, 13. ftaubastrum incisum, ..... 146 



Fig. 14. " " six rayed form, . . 146 



Figs. 15, 16. Staueastriim distentum, . . 165 



17, 18. Staurasteum Eloiseanum, . 164 



" 19-25. Statjeastrum enobme, ..... 166 



" 26-28. Staurastrtim ai,tebnans, . 142 



" 29, 30 Staubasteum scabrtjm, 144 



" 31-35. Stadrastbum margaritaceum, . . ' 138 



" 36-38. Staubastrum tbicorne, . .138 



" 39, 40. Staurastrum paniculosum, . . . 137 



" 41, 42. Statjeastrum eugitlosum, . . . 140 



" 43-45. Staubastrum pttoctulatum, . . . .141 



* Compare note under St. incisum, p. 146. This species from ponds, New Jersey, 

 was described in tlie " Bull. Tor. Bot. Clvib, New York, 1880." Membrane smooth ; 

 end view flve-rayed ; apices of rays obtusely rounded, bases wide, separated by a 

 rounded sinus. 



