LAGENIDIALES 981 



5-7 X 7-9 \i, and broadly fusiform, 5-6 x 9-10 u.. Oospores spherical, 

 7-14 [x, oval, 7-9 X 10-1 1 [x; content hyaline and granular with a large 

 vacuole; wall hyaline and smooth, 1.5-2 \x thick; germination unknown" 

 (Karling, he. cit.). 



Parasitic in the bodies of rotifers, Distyla sp., Brazil. 



The perfectly globose, thick-walled sporangia and the simplicity of 

 the sex organs make it quite evident that this species belongs in Myzo- 

 cytium. 



Since no encysted zoospores were found on the outside of the rotifer, 

 it was considered probable that the zoospores had been engulfed and 

 the animal thus infected. 



IMPERFECTLY KNOWN SPECIES OF MYZOCYT1UM 



? Myzocytium irregulare H. E. Petersen 



Bot. Tidsskrift, 29:403, fig.xvi a, d, 1909; Ann. Mycologici, 8:538, fig. xvi a,d. 



1910 



Sporangia short-cylindrical, globose, or irregular in shape, articu- 

 lation variable, most frequently in pairs, often forming short branches 

 when more than two, discharge tube of variable length, usually expanded 

 beneath the host wall; zoospores and sex organs not observed. 



In Cosmarium sp., Micrasterias sp., H. E. Petersen (he. cit.), Sparrow, 

 Denmark; Cosmarium sp., Scherffel (1914: 17), Hungary; Micra- 

 sterias rotata, Cejp 1 (1933a: 8, pi. 1, fig. 16), (?) Type III on M. denticula, 

 Reinsch (1878: 300, pi. 17, figs. 8, 13), Germany; Micrasterias sp., W. 

 G. Farlow (F. 384), United States. 



As Petersen states, the inclusion of this fungus in Myzocytium rather 

 than in Lagenidium is questionable. In the branched or lobed nature of 

 its thallus it is closer to Lagenidium. A similar situation is found in M. 

 lineare and M. zoophthorum. In the latter, however, the absence of a 

 specialized antheridium appears to relate the species to Myzocytium 

 rather than to Lagenidium. Since, apparently, no sex organs (or even 

 zoospores) have as yet been described in the present fungus, the anther- 

 idial character cannot be used in this instance to determine the genus. 

 Figure XVI d (Petersen, he. cit.) is believed by Canter (1947a) to 

 represent Myzocytium megastomum. 



1 Czechoslovakia. 



