PLATE CXLIII. 



FIGS. PAGE 



1-3. Staurastrum polymorphum Breb. 1, x 520 ; 2*, 



X 510 ; 3, X 840 . . .125 



4*. St. polymorphum var. pusillum West. X 510 . 127 

 5. St. polymorphum var. simplex W. & G. S. W. X 



400 '. . . . .128 



6. St. polymorphism var. munitum West. X 520 . 129 



7-8 S*. inflexum Breb. 7, X 520 ; 8*, X 510 . 108 



9-13. . crenulatum (Nag.) Delp. X 520 . . 110 



14-16. St. proboscidium Perty. 14 and 15, forms, X 500 



and 520 respectively ; 16, X 400 (after Ralfs) . 129 

 17. St. bicorne Hauptfl. X 460 (after Haptfleiscuh) . 117 

 18-19.^. oxyacanthum Arch. 18*, X 510 ; 19*, X 510 169 

 20-22. St. oxyacanthum var. polyacanthum Norclst. 20*, X 

 510 ; 21*, basal view of semicell, X 510 ; 22*, 

 vertical view, x 510 . . ,170 



23 St. eboracense Turn. X 500 137 



