134 A Q UA TIC PH YCOMYCETES 



The sporangia wore closely packed in linear series. As Fischer (1892: 

 24) has suggested, this may in reality be a species of Myzocytium or, 

 but less likely, of Catenaria. 



Gwynne-Vaughan and Barnes (1937: fig. 11) and Sparrow (1936a: 

 427. pi. 14, lie. 1) figured a fungus on filamentous Conjugatae in Eng- 

 land which has ellipsoidal sporangia, as does the present species, but 

 differs from it in having a short stout discharge tube only slightly in- 

 flated basally. Future studies of Olpidium endogemun may allow the 

 inclusion of this \ariety. 



Karling (1941b: 108) has reported this desmid parasite from the 

 United States in pollen grains of Pinus. No details are given. 



The fungus in Cylindrocystis brebissonii with cylindrical to bottle- 

 like sporangia, 1 8 42 u, long by 1 1-14 u. broad with a terminal discharge 

 tube 6-10 u. by 4 u. and an endobiotic swelling, found by Fott (1950: 8, 

 lies. 15-18) in Czechoslovakia, is probably, as he indicates, distinct 

 from O. endogenum. It has certain affinities with O. tuba Sorok. and 

 O. immersum Sorok. 



Olpidium zygnemicola Magnus 

 Verhandl. Bot. Vereins Prov. Brandenburg, 26: 79. 1885 



Sporangium formed between the wall and the contents of the alga, 

 resting directly on the protoplasm, spherical, colorless, smooth-walled, 

 with a discharge tube which does not project beyond the outer wall 

 of the alga: /oospores uniflagellate: resting spore within the host con- 

 tents, spherical, with a faintly mottled thick smooth wall and a large 

 oil globule, germination not observed. 



In Zygnema sp., Germany. 



The location of the sporangium between the wall and the protoplasm 

 of the alga is by itself of little significance as a character in maintaining 

 this species distinct from Olpidium entophytum. All gradations in po- 

 sition are often found in an algal cell heavily infected with a species 

 of Olpidium. 



Olpidium rostrieerum Tokunaga 

 Trans. Sapporo Nat. Hist. Soc., 13: 80, pi. 5, fig. 11. 1933 

 rangia spherical to ovoid, 14.4 25.2 / in diameter, singly or from 



