TO THE MEMORY OF 



HENRY GROVES 



(1855-1912), 

 A TRUE NATURALIST, 



WHO DID MUCH TO ADVANCE THE STUDY OF 



THE BRITISH CHAROPHYTA, AND UPON WHOSE WORK 



MUCH OF THE SYSTEMATIC PORTION OF THE 



FOLLOWING PAGES IS BASED, 



THIS WORK IS DEDICATED 

 BY HIS BROTHER AND HIS FRIEND. 





. 





