42 SPECIES OF ALG^E. 



Oogonia globose or nearly so (A). 



" ellipsoid or nearly so; oospores longitudinally crenulate- 



costate (F). 

 A. Dwarf males i celled, on or near the oogonia, elachistandra, 97 



A. " " 2 celled (B). 



B. Basal part (stem) of dwarf males, shorter than the spermogonia (C). 



B. " " " " " " longer than the spermogonia; 

 oospore warty gigantea, 99 



C. Diameter of veg. cells 20/4 or less (D). 



C. " " " " more than 20/4; oospore granulate, 



setigera, 98 



D. Oogonia without terminal seta intermedia, 97 



D. " with terminal seta, or beneath a male cell (E). 



E. Dissepiment supporting oogonia in the middle of cell or .slightly 



below crenulata, 97 



E. Dissepiment above the middle of the cell .... polyandry 98 



E. " below the middle Brebisonii, 99 



F. Monoecious (G). 



F. Dioecious (H). 



G. Diameter of oogonia 27-35/4 v 46-56/4 .... mirabilis, TOO 



G. " " 20-25/4 by 33-36/1 nana, 100 



H. Dissepiment of cells supporting oogonia obsolete (I). 



H. " " " " " present (J.) 



I. Diameter veg. cells 12-5/1, length less than diameter, pygmcea, 101 



J. Diameter veg. cells 16/4 or less (K). 



J. " " " more than i6ju (L). 



K. Veg. cells 1-1.5 times as long as wide .... subsimplex, 101 



K. " " 2-3.5 " " " " " repanda, 102 



K. " " I -5~ 2 " " " " " ... rhadinospora, 103 



L. Veg. cells 2.5-4.5 times as long as wide .... insignis, 101 



L. " '* 1.5-3 " " " 4< " minor, 101 



L. " " 1.25-3 " " " " "... rectangularis, 102 



12. SPH^EROPLEA. 



Cells 8-10-20 times as long as broad, chlorophyllose rings 20-30 in 

 each annulina, 104 



13. CYLINDROCAPSA. 



Ends of cells clear and pearly amcsna, 105 



Ends of cells not clear geminella, 104 



