PLATE C. 



FIGS. PAGE 



1. Cosmarium mar gar it at um (Lund.) Roy & Biss. 



forma subrotundata W. & Gr. S. West. x 500 19 

 2. C. Quadrum var. sublatum (Nordst.) "W. & Gr. S. 

 West, x 500. An Australian specimen figured 

 here for comparison with C. Quadrum, of which 

 it is probably but a variety . .21 



3-6. C. Quadrum Lund. 3, x 400 (after Luiidell) ; 4, 



x 500 ; 5 and 6, x 520 . . . 20 



7-8. C. Pseudobroomei Wolle. x 520 . . 22 



9. C. Pseudobroomei var. convexum W. & Gr. S. West. 



x 400 . 23 



10. C. Subbroomei Sclimidle. a, x 420; b, x 500 (after 



Schmidle) . . . .23 



11. C. Subbroomei forma. x 520 . . 24 



12. C. Broomei Ealfs. x 400 (after Ralfs) . 24 



