PLATE CLIII. 



FIGS. PAGE 



1-4. Staurastrum aculeatum (Ehr.) Menegli. 1, X 520 ; 

 2, another form, X 520 ; 3, X 520 ; 4*, vertical 

 view, X 510 . . . .160 



5. St. vestitum var. subanatinum W. & G. S. W. x 



520 . . . . . 159 



6*-7*.St. Archerii West, X 510 155 



