CHYTRIDIALES 303 



? Rhizophydium epithemiae Valkanov 

 Arch. Protistenk., 73: 362, fig. 2. 1931 



Sporangium sessile, spherical, up to 21 jx in diameter, colorless, 

 with a prominent thick-walled subapical wartlike protrusion, wall 

 otherwise thin, smooth; rhizoids fairly stout, short, branched, arising 

 from a short main axis; zoospores not observed, apparently emerging 

 through a fairly large lateral pore; resting spore not observed. 



Parasitic on Epithemia zebra, Bulgaria. 



The curious wartlike protrusion may possibly be the case of the 

 infecting zoospore which, as in Chytridium schenkii, has persisted. 



? Rhizophydium fallax Scherffel 

 Arch. Protistenk., 53: 30, pi. 2, figs. 60-62. 1925 



Sporangium sessile, spherical, variable in size, wall smooth, color- 

 less, fairly thick; endobiotic part not distinctly observed, being sur- 

 rounded by a large pale reddish-brown peglike thickening of the host 

 wall ; zoospores narrowly ovoid, with a colorless lateral oil globule and 

 a short slowly moving posterior flagellum attached to the narrower 

 end of the body, emerging individually through one (or more ?) mi- 

 nute needle-like scarcely perceptible lateral pore, movement gliding 

 or amoeboid, never hopping; resting spore epibiotic, sessile, spherical, 

 8-10 \x in diameter, with a smooth double wall 1 fx thick, contents 

 with a large (8 [x in diameter) colorless eccentric globule or with from 

 two to three globules, endobiotic part like that of the sporangium, 

 germination not observed; companion cells one or two, smooth-walled, 

 3 [x in diameter, directly attached to the receptive thallus (resting 

 spore), wall at first thin, later thickening. 



On Mougeotia sp., Hungary. 



Differing from Rhizophydium globosum in lacking a prominent exit 

 pore and in having ovoid gliding spores and smooth colorless resting 

 spores. 



Further observations on the endobiotic system will be necessary 

 to determine whether this is a species of Rhizophydium or of Phlyctid- 

 ium. 



