PLATE CXXXI. 



FIGS. PAGE 



1-3. Staurastrum jaculiferum West. 1, quadrangular 



form, X 520 ; 2 and 3, triangular forms, X 520 16 

 4-5. St. jaculiferum var. excavatum W. & G. S. W. 4, 



X 520 ; 5, biradiate form, X 520 . . 18 



6. St. jaculiferum var. subexcavatum W. & G. S. W. 



X 430 . . . .18 



7-8. St. megacantlium Lund. X 520 . . 20 



9-10. St. megacanfhum var. scoticum W. & G. S. W. 



X 520 21 



