PLATE L. 



Figures magnified 500 diameters. 



PAGE. 



Figs. 1, 2. STAURASTRUM TUMIDX-M, front and end views, . . 133 



" 3, 4. STAURASTRUM GRANDE, front and end views, . . 133 



" 5, 6. STAURASTRUM MAJUSCULUM, front and end views, . . 133 



" 7,8. STAURASTRUM MAGNUM, front and end views, . . 133 



" 9, 10. STAURASTRUM ORBK-ULARE, front and end views, . . 132 



" 11,12. STAURASTRUM MUTICUM, front and end views, . . 131 



Fig. 13 Var. ellipticum, ... . 132 



Figs. 14, 15. Var. minus, . . 131 



