PLATE LXXIX. 



FIGS. PAGE 



12. Cosmarium reniforme (Ralfs) Arch. x 500 . 157 

 3-4. C. reniforme var. compression Nordst. 3, x 



400 (after Nordstedt) ; 4, x 520 . . 158 



5. C. reniforme var. apertum West & Gr. S. West. 



x 500 . . . . 159 



6. C. reniforme var. elevatum West & Gr. S. West. 



x 562 . . . .159 



7. C. reniforme. A form approaching var. ele- 

 vatum. x 520 . . .159 

 8. C. Tnrnerii Roy. Zygospore, x about 300 



(after Ralfs) . . . .160 



9. C, Turnerii. x 520 . . .160 



10-11. C. Brcbissonii Menegh. x 500 . .161 



