PLATE XX. 



Tolypella nidifica Leonhardi. 



FIG. 



1 . Plant, natural size. 



2. Apex of branchlet. x c. 12. 



3. Fruiting branchlet. X c. 12. 



4. Oogonium, x c. 40. 



5. Apex of oogonium with coronula. x c. 80. 



6. Apex of mature oogonium after shedding coronula. x c. 50. 



7. Oospore, x c. 50. 



Fig. 1 from the Baltic at Valje. Figs. 2-7 from Wexford. 



