226 AQUATIC PHYCOMYCETES 



the resting spore. This peculiarity is shown by several other chytrids, 

 ootably Nowakowsk iella hemisphaerospora. 



KEY TO THE SPECIES OF SEPTOSPERMA 



Sporangium ovoid or ellipsoid; resting spore same shape as sporan- 

 gium S. anomalum, p. 226 



Sporangium spherical to pyriform; resting spore clavate 



S. rhizophidii, p. 226 



Septosperma anomalum (Couch) Whiffen 



Mycologia, 34: 552. 1942 



Phlyctidium anomalum Couch, J. Elisha Mitchell Sci. Soc, 47: 256, pi. 17, 

 figs. 69-83. 1932. 



Sporangium sessile, ovoid, or ellipsoid, smooth-walled, 3.8-6.1 \x 

 broad by 12 u. high; haustorium bulbous or discoid; zoospores 8-30, 

 spherical, 2.3 \i in diameter, with a single glistening droplet, discharged 

 through an apical pore, the sporangium collapsing, more or less, 

 after spore discharge; resting spores formed from a cell of about the 

 same size and shape as mature sporangium, the protoplasm col'ecting 

 in the distal half of the cell, which becomes thick-walled, leaving the 

 proximal half empty, with one to three oil globules, rarely occupying 

 the entire (parent) cell. 



Parasitic on sporangia of Phlyctidium bumil/eriae, Couch (loc. ciU), 

 United States; P. bumilleriae, Berczi (1940: 80, pi. 2, figs. 7-10), 

 Hungary; Chytriomyces tabellariae, Canter (1949a: 19, fig. 3), Zygo- 

 rhizidium willei, Micromyces sp., Rhizopliydium planktonicum (Canter, 

 1953:288), Great Britain. 



In this curious example of hyperparasitism of one chytrid by another, 

 both Couch and Canter noted that none of the infected sporangia of 

 the host ever reached maturity. Canter further observed that the resting 

 spores of the host were never attacked. 



Septosperma rhizophidii Whiffen 

 Mycologia, 34: 552, figs. 28-52. 1942 

 (Fig. 19 L-M, p. 318) 

 "Zoosporangia varying in shape from spherical to pyriform, 8.2 u. 





