754 AQUATIC PHYCOMYCETES 



Rhizidiomyces apophysatus Zopf 



Nova Acta Acad. Leop.-Carol., 47: 188, pi. 20, figs. 1-7. 1884 

 (Fig. 55 E-G, p. 752) 



Sporangium spherical, subspherical, or broadly pyriform, 18-45 [x in 

 diameter, wall of cellulose, stout, smooth or with short spines, colorless 

 or faintly golden brown, with an apical or subapical long cylindrical dis- 

 charge tube; rhizoids richly branched, arising from one or two stout 

 main axes at the base of a pyriform, or occasionally spherical or fusi- 

 form, subsporangial apophysis up to 18.5 \x in diameter; zoospores 

 formed outside at the apex of the discharge tube, ovoid or oblong with 

 rounded ends, 3.7-6 \x (long?), with a few minute gleaming granules and 

 a short anterior flagellum, movement swimming or feebly amoeboid; 

 resting spore not observed. 



Parasitic on oogonia of Saprolegnia ferax, S. asterophora, Achlya 

 polyandra, Zopf (loc. cit.), Germany; Achlya conspicua, A. apiculata, 

 Coker (1923: 186, pi. 63), "Saprolegnian," cultivated on pollen of 

 Liquidambar, nutrient agar, Couch (1939a), Achlya sp., Sparrow 

 (1932b: 282, fig. 3e), A.flagellata, Karling (1943: 644), United States; 

 Achlya flagellata, Tokunaga (1934b: 391, pi. 1 1, fig. 10), Japan; host (?), 

 Forbes (1935b: 3), Great Britain; Achlya klebsiana, Chaudhuri and 

 Kochhar (1935: 150, pi. 12, figs. 24-29), India; oogonia of Saprolegnia 

 and Achlya, Cejp (1934: 228), Czechoslovakia; oogonia of Achlya 

 flagellata, Karling (1944d: 392, figs. 1-34), Brazil; ? Vaucheria sp., 

 Berczi (1940: 84, pi. 2, figs. 23, 24), Hungary; from soil, pine pollen, 

 Gaertner (1954b: 22), Northwest Africa, West Africa, Equatorial 

 East Africa, South Africa. 



Whether or not a discrete vesicle is formed around the maturing spore 

 mass is open to question. Karling (1944d) believes that only a thickened 

 plasma membrane is around the periphery. 



Rhizidiomyces bivellatus Nabel 



Arch. f. Mikrobiol., 10: 537, figs. 1-7. 1939 



Sporangium spherical, 80-100 jo. in diameter, wall smooth, light 

 brown, becoming dark and rough with age, in young plants consisting 

 of two layers, the inner wall of chitin and evanescent and the outer of 



