PLATE XIX. 



Tolypella glomerata Leonhardi. 



riG. 



1. Plant, natural size, from Staines, Middlesex. 



2. Part of plant, natural size, showing persistent proembryonic 



growth. 



3. Fruiting branchlet. x c. 20. 



4. Oogonium, x c. 40. 



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



6. Oospore, x c. 40. 



