PLATE XXXIX. 



Figures magnified 500 diameters. 



Figs. ). "_'. Si \i rastrum tumidi m, fronl :m<l end view, 



3, \. Staurastrum granoe, front and end view, 



5,6. Staurastrum majuscclum, front and end view, 



7,8. Staurastrum magnum, front and end view, 



" i, 10. Staurastrum orbiculare, front and end view, 



11, 12. St aurasi in m mi mi m. fronl and end view, 

 Fig. 13. - Var. ellipticum, 



Figs. 14, 15. " - Var. minor, 



P m.i . 



. 120 

 120 



. 121 

 120 



. 120 

 119 

 119 

 119 



