CHYTRIDIALES 307 



siphonia. Observations on the escape and flagellation of the zoospores 

 and on the nature of the endobiotic part are needed to confirm the 

 present generic disposition of the species. 



The fungus termed Rhizophydium polysiphoniae (Cohn) Petersen by 

 Martin (1922: 236, figs. 1-10) may, because of its thick wall and some- 

 what angular sporangia, possibly be referred to R. discinctum. Martin's 

 fungus, however, possessed a relatively extensive branched rhizoidal 

 system. If this had been present in R. discinctum it seems probable that 

 the two observers would have seen it. 



Sparrow considered that his fungus, which appeared on Ceramium 

 maintained in a laboratory aquarium for a week, was only weakly if 

 at all parasitic. 



? Rhizophydium gelatinosum Lind 

 Ann. Mycologici, 3: 427, 3 figs. (p. 427). 1905 

 Sporangium sessile, spherical, 20-30^ in diameter, with a short 

 stalklike base, wall thin, smooth, colorless, surrounded by a gelatinous 

 hull about 3 [L thick; rhizoids not observed; zoospores not observed, 

 apparently escaping through eight sessile pores 4-6 y. in diameter formed 

 on the upper surface of the sporangium; resting spore not observed. 

 On Acrosiphonia (Cladophora) pallida, coll. Svedelius, Sweden. 

 The organism is remarkable for the number of pores formed and 

 for the thick gelatinous sheath which surrounds the sporangia. That 

 the structure is fungoid at all is doubtful. 



? Rhizophydium marinum de Wildeman 

 Ann. Soc. Beige Micro. (Mem.), 17: 11. 1893 

 Sporangium sessile, spherical, 7-15 jx in diameter, wall smooth, 

 colorless; rhizoids few; zoospores and resting spore not observed. 

 On Melosira sp., in marine aquarium, Belgium. 

 Possibly a marine form of the "Rhizophydium globosum" type, as 

 are those mentioned by Sparrow (1936b: 258). 



? Rhizophydium sp. Aleem 

 Arkiv. f. Botanik, 3: 15, fig. 30. 1953 

 Sporangium spherical, 17 p in diameter, with a thin, smooth wall, 



