PLATE XVI. 

 Nitella hyalina Agardh. 



FIG. 



1. Plant, three-quarters natural size, from Looe Pool, 



Helston, W. Cornwall. 



2. Portion of whorl showing primary, and upper and lower 

 ' accessory branchlets. x c. 6. 



3-7. Apices of dactyls, x c. 45. 



8. Branchlet-node with antheridium. x c. 22. 

 9, 10. An upper and a lower shield of antheridium. x c. 45. 



11. Oogonium, x c. 22. 



12. Apex of oogonium with coronula. x c. 100. 



13. Unripe oospore, hroad view, x c. 22. 



14. The same, viewed edgewise, x c. 22. 



