PLATE LVIII. 



Figures magnified oOO diamo tors. 



PAOB. 



Figs. 1, 2. STAURASTROM TRICORNUTUM, front and end views, . . 159 



3, 4. STAURASTRUM Nov.* CJESARE^E, front and end views, . 159 



5, 6. STAURASTRCM SPONOIOSUM, front and end views, . .163 



7,8. other form, front and end views, 163 



9, 10. STAURASTRUM ARCTICON, (M. iuqpij,um Wood), . . 163 



