CHYTRIDIALES 



93 



4. Zygorhizidium Lowenthal (Archiv fur Protistenkunde, 5 : 228, 

 pi. 8, 1904). 

 Erected on the single species, Z. willei Lowenthal, in Cylin- 

 drocystis in Norway. 



Fig. 23.- — Podochytrium clavatum Pfitzer in Pinnularia. (a) Young plant. 

 {b, c) Mature plants showing subsporangial extramatrical stalk. (After Zopf 

 1888.) 



Fig. 24. — Rhizidiomycrs apophysatus Zopf in oogonium of Achlya. A. sporangia. 

 B. stages in swarmspore formation. {After Zopf 1884-) 



5. Rhizidiomyces Zopf (1884: 188). 



Two species, K. apophysatus Zopf (Fig. 24), in the oogonia of 

 Achlya and Saprolegnia, originally described from Europe and 



