374 AQUATIC PHYCOMYCETES 



becoming strongly expanded main axes where they join the sporangium; 

 zoospores from thirty to forty in large sporangia, discharged through 

 a pore formed in the epibiotic apiculus; resting spore not observed. 



In moribund vegetative cells and gametangia of Spirogyra crassa, 

 Zopf (loc. cit.), Germany; Spirogyra crassa, Oedogonium sp., de Wilde- 

 man (1890: 7; 1891 : 172), Belgium; Spirogyra crassa, Atkinson (1909a: 

 338), United States; Oedogonium sp., Valkanov (1931a: 363), Bul- 

 garia; vegetative cells of Zygnema and Mougeotia, Domjan (1936: 46, 

 pi. 1, figs. 71, 82-83), Oedogonium s/?., Berczi (1940:86), Hungary; 

 Oedogonium sp., Litvinow (1953: 82), Latvia; Spirogyra sp., Richards 

 (1956: 263), Great Britain. 



As in Entophlyctis apiculata, the cyst of the infecting zoospore in this 

 species is persistent and functions in spore discharge. Neither empty 

 sporangia showing this pore nor zoospores were described by Zopf. 

 Empty sporangia figured by Domjan, however, bear out Zopf's con- 

 tention that the apiculus functions as a discharge tube. 



Valkanov gives the diameter of the sporangium as 17-18 \x; Domjan 

 records the size as 10-15 by 7.5 10 \i, with the knob 3.7-7.5 \x in diam- 

 eter. 



Entophlyctis rhizina (Schenk) Minden 



Kryptogamenfl. Mark Brandenburg. 5: 354. 1911 (1915) 



Chytridium rhizinum Schenk, Verhandl. Phys.-Med. Gesell. Wurzburg, A. 

 F., 8:238, pi. 5, figs. 6-13. 1858. 



Sporangium spherical or somewhat ovoid, 8-27 \± in diameter, wall 

 smooth, usually double-contoured, forming a single extramatrical dis- 

 charge tube (rarely two) 4—14 ^ long by 1 jjl in diameter; rhizoids 

 arising from one or more places on the lower side of the sporangium, 

 branched, somewhat stout, with a visible lumen as they approach the 

 sporangium; zoospores spherical, 2 u, in diameter, with a reddish yellow 

 globule and a rlagellum: resting spore not observed. 



In Voucher ia geminata, V. sessilis, Schenk (loc. cit.), Germany; 

 Voronichin (1920: 10), Russia; Spirogyra maxima, Berczi (1940: 86, 

 pi. 1, figs. 1-5, 8, pi. 2, fig. 39), Hungary; Vaucheria sp., Litvinow 

 (1953:82), Latvia. 



