PLATE CXXIX. 



FIGS. PAGE 



1*. Staurastrum disputatum W. & G. S. West, forma 

 minor, X 630. [ Consult vol. iv,p. 176, PL CXXVI, 

 fig. 16.] 

 2-6. St. glabrum (Ehr.) Ealfs. 2 and 3, X 520; 4 and 



5, larger forms, X 520 . . .2 



6-8. St. apiculatum Breb. 6 X 520 ; 7*, X 510 ; 8, 



zygospore, X 520 . . .6 



9-12. Z. dejectum Breb. 9 and 10, X 520 ; 11, form 

 with parallel spines, X 520 ; 12, zygospore, X 

 720 (after Beinseh) . . .7 



13. St. dejectum forma major W. & G. S. W. X 520 . 9 

 14-15. St. Dickiei Ralfs. 14, X 520 ; 15, zygospore, 



X 356 . . . .3 



16. St. Dickiei var. circidare Turn. X 520 . 5 



17. St. Dickiei var. rhomboideum W. & G. S. W. 



X 520 5 



