CHYTRIDIALES 



95 



Fig. 26. — Harpochytrium hedenii Wille on Spirogyra and Zygnema {a-c) 

 Young thalli developed from swarmspores. (d) Mature plant, (e) Zoospores 

 escaping in amoeboid state; secondary sporangium forming below primary. 

 (J, g) Uniciliate swarmspores escaping; proliferation of sporangia, {h) One 

 individual of Harpochytrium attacked by another. (After Atkinson 1903.) 



10. Siphonaria Petersen (Jour, de Botanique, 17: 220, 1903). 



Erected on a single species, *S. variabilis Petersen saprophytic 

 in empty nymph cases lying in water. 



