934 AQUATIC PHYCOMYCETES 



Parasitic in the hyphae, sporangia, and so on, of Achlya sp., Brazil. 



Related to Olpidiopsis saprolegniae var. levis Coker by reason of the 

 smooth-walled resting spore and the possession of a companion cell. 

 In view of Shanor's (1940) demonstration that O. saprolegniae is con- 

 fined to Saprolegnia and Isoachlya, the present fungus on Achlya is 

 maintained as a distinct entity. 



Olpidiopsis fusiformis Cornu 

 Ann. Sci. Nat. Bot., V, 15: 147, pi. 4, figs. 1-4. 1872 

 Pseudolpidium fusiforme Fischer, Rabenhorst. Kryptogamen-Fl., 1(4): 35. 



1892. 



Olpidiopsis minor Fischer, ibid., p. 39. 1892. 



Pseudolpidium stellatum Sawada, Special Bull. Agr. Exp. Sta. Formosa, 

 3:70, pi. 8, figs. 11-16. 1912. 



Sporangium causing swelling of the host hypha, usually fusiform, 

 also ellipsoidal or cylindrical, 45-350 u- long by 18-78 u. in diameter, 

 with a thin, smooth or spiny, colorless wall, variable in size; zoospores 

 ovoid 4 n long by 2 { x wide, biflagellate; resting spore frequently ellip- 

 soidal, or spherical, colorless, thick-walled, the outer surface sparingly 

 covered with broad subulate spines which are joined at their bases to 

 form a reticulum, contents with globules, germination not observed; 

 companion cell spherical, smooth-walled, smaller than the resting spore. 



Parasitic in hyphae of Achlya leucosperma, A. racemosa, Achlya sp., 

 Cornu (loc cit.), France; Achlya racemosa, Reinsch (1878: 304, pi. 17, 

 figs 1-4) Achlya sp., Fischer (loc. cit.), Minden (1915: 265), Germany; 

 Achlya polyandra, E. J. Butler (1907: 134, pi. 9, figs. 8-11), India; 

 Achlya sp. H. E. Petersen (1909: 406; 1910: 541, fig. 18g), Denmark; 

 Achlya sp., Sparrow (1932b: 270, fig. 1 f-g), A. imperfecta, Achlya spp., 

 Shanor (1939b: text fig. 2, pi. 25, fig. 2; 1940), United States; Achlya 

 flagellata, A. flagellata var. yezoensis, A. racemosa, Tokunaga (1933a: 

 23, pi. 2, figs. 6-8), Japan; Achlya racemosa, Achlya sp., Cejp (1934: 228, 

 fig's. 1-2), Czechoslovakia; Achlya sp., Shen and Siang (1948: 199), 



China. 



For convenience the records of Pseudolpidium fusiforme are listed 



separately : 



Parasitic in hyphae (not confined to the apex) of Achlya polyandra, 



