944 AQUATIC PHYCOMYCETES 



refractive granules, size unknown; one flagellum inserted near the 

 anterior end, the other laterally; swimming motion smooth, body of 

 spore often revolving on its long axis. Resting spores parthenogenetic, 

 single or numerous, occurring in association with the zoosporangia, 

 spherical to oval, 12-27 u. exclusive of spines, yellowish, containing a 

 large refractive globule surrounded by a peripheral layer of vacuolate 

 protoplasm; endospore .7 to 1.2 \x thick, exospore 1.7 to 2.5 \x thick 

 and covered with long, 4 \x, tapering, thick, crowded spines; germination 

 unknown; companion or male cells lacking" (Karling, he. cit.). 



Parasitic in Pythium intermedium, Butler (Joe. cit.), France; Pythium 

 rostratum, Whiffen (1942b: 607, figs. 7, 8), United States; ? host, soil, 

 Remy (1948:214), Germany; from soil, substrate?, Gaertner (1954b: 

 22), Equatorial East Africa. 



"Causing terminal enlargements and lateral, oval- or balloon-shaped 

 diverticula in the host hyphae which may be 80-90 \x in their greatest 

 diameter" (Karling, op. cit., p. 47). 



Olpidiopsis pythii (Butler) Karling 

 Simple Holocarpic Biflagellate Phycomycetes, p. 47. 1942 



Pseudolpidium pythii Butler, Mem. Dept. Agr. India, Bot. Ser., 1 : 129, pi. 7, 

 figs. 9-16. 1907. 



"Zoosporangia solitary or numerous, hyaline, smooth, oval, and 

 ellipsoid, up to 35 [J. in the greatest diameter, with a single exit tube of 

 varying length which extends for a short distance beyond the surface of 

 the host. Zoospores isocont, hyaline, uniequilateral, somewhat kidney- 

 shaped with one to several small refractive granules; flagella laterally 

 inserted; swarming in the vicinity of the exit canal for a brief period, 

 then coming to rest for a few minutes in a dense cluster; finally swim- 

 ming away slowly. Resting spores parthenogenetic, solitary or numer- 

 ous, often in association with zoosporangia, oval or spherical, 19.2-30 

 u., brown, comparatively thin-walled and covered with fine, thread-like, 

 short, evenly spaced spines; germination unknown; companion or male 

 cells lacking" (Karling, he. cit.). 



Parasitic in Pythium monospermum, P. rostratum, P. vexans, and P. 

 intermedium, Butler (he. cit.), France; Pythium sp., Minden (1915: 



