PLATE VII. 

 Nitella opaca Agardh. 



FIG. 



1. Male plant ; natural size, from Ashstead, Surrey. 



2. Female plant, natural size, from Wandsworth Common, 



Surrey. 

 3-6. Apices of dactyls, x c. 40. 



7. Apex of dactyl of var. attenuata from near Hythe, 



S. Hants, x c. 40. 



8. Branchlet-node with antheridium. x c. 20. 



9. Branchlet-node with oogonia. x c. 20. 



10. Mature oogonium after shedding coronula. x c. 40. 



11. Oospore. x c. 40. 



