CHYTRIDIALES 209 



Epibiotic part typically with a sterile septate base or a small 

 knoblike structure on which the sporangium rests; endo- 

 biotic part knoblike or rhizoidal 



Sterile part an inconspicuous knob on which the sporan- 

 gium rests; endobiotic part knoblike 



Physorhizophidium, p. 358 

 Sterile part conspicuous and an integral component or con- 

 tinuation of the base of the fertile portion, rarely 

 lacking; endobiotic part rhizoidal or straplike 



PODOCHYTRIUM p. 359 



Body of the encysted zoospore either sessile and enlarging to form 

 a prosporangium or lying free in the water, not enlarging, 

 and producing at the tip of the germ tube an appressorium 

 which expands to form the sporangium; sterile base never 

 formed 



Body of the encysted zoospore sessile, enlarging to form a pro- 

 sporangium, the endobiotic part consisting of a series of 



intercommunicating broad lobes Saccomyces, p. 364 



Body of the encysted zoospore producing at the tip of a germ 

 tube an appressorium which expands to form the sporan- 

 gium, endobiotic part completely rhizoidal, or apophysate 

 and bearing a distal complex of stubby digitations 



Endobiotic part not apophysate Scherffeliomyces, p. 365 



Endobiotic part apophysate Coralliochytrium \ p. 368 



Sporangium endobiotic, resting spore endobiotic; vegetative system 

 rhizoidal; zoospore cyst usually evanescent 



Subfamily Entophlyctoideae, p. 369 

 Vegetative part rhizoidal, generally monophagous 



Sporangium spherical, pyriform or irregular, never strongly 

 tubular; typically forming a single discharge tube or pore 

 Sporangium formed from a localized primary swelling at the 

 tip of the germ tube or from a secondary expansion of 

 the more proximal part of the rhizoidal rudiments 

 Rhizoids or rhizoidal axes arising directly from the spo- 

 rangium Entophlyctis, p. 369 



Rhizoids arising from an apophysis . . . Diplophlyctis, p. 383 

 Sporangium formed by vesiculation of the dorsal side of the 

 rhizoids, strongly dorsi-ventrally differentiated 



Phlyctorhiza, p. 391 



Sporangium strongly tubular; forming one or more dis- 

 charge tubes Mitochytridium, p. 395 



1 Johns (1956) has merged this genus with the preceding. 



