PLASMODIOPHORALES 783 



Parasitic in Achlya glomerata, coll. F. Foust, United States. 

 Some cytological details are given by Whiffen (1939)- 



Octomyxa brevilegniae Pendergrass 

 J. Elisha Mitchell Sci. Soc, 64: 133, pi. 15. 1948 



"Obligate parasite in Brevilegnia linearis Coker and Geolegnia inflata 

 Coker and Harvey, causing spherical galls mostly on the ends of the 

 hyphae of the host. Mature galls 30-90 \x thick. Plasmodia of the par- 

 asite at maturity completely filling the galls and segmenting into zoo- 

 sporangia; plasmodia developed later segmenting into resting spores in 

 clusters of eight. Zoosporangia globose to ovoid, 5.2-7.6 \x mostly 7 \x, 

 in diameter, thin-walled. Spores discharged through papillae which are 

 formed only on some of the sporangia next to the host wall, the other 

 peripheral sporangia and those deeper within the sorus discharging 

 their spores through those furnished with papillae; zoospores biflagel- 

 late with one long posterior and one short anterior flagellum, 4-6 in a 

 zoosporangium. Resting spores 2.8-4.9 \x, mostly 3.5 \x in diameter, 

 with smooth, somewhat thickened walls ; germination unknown" (Pen- 

 dergrass, loc. cit.). 



Parasitic on Brevilegnia sp., Geolegnia inflata, not capable of infecting 

 Achlya, Saprolegnia, Aplanes, Dictyuchus, Isoachlya, Allomyces, or Apo- 

 dachlya, United States. 



Details of the development and structure of this species were de- 

 scribed later by Pendergrass (1950: 279, figs. 1-29). Although Geolegnia 

 was infected artificially, attempts to inoculate representatives of other 

 saprolegniaceous genera were unsuccessful. 



PLASMODIOPHORA Woronin 



Arbeit. St. Petersburg Naturf. Gesell., 8: 169. 1877; Jahrb. wiss. Bot., 1 1 : 548. 



1878 



Ostenfeldiella Ferdinandsen and Winge, Ann. Bot. London, 28: 648. 1914. 



"Resting spores lying free in host cell, not united in cystosori, var- 

 iable in size and shape, usually producing one zoospore in germination. 

 Zoospores anteriorly biflagellate and heterocont, becoming intermit- 

 tently amoeboid, infecting the host as an amoeba (?), dividing and 



