CHYTRIDIALES 471 



endobiotic, branched, extensive, with fusiform swellings; zoospores 

 spherical, uniflagellate, with a small refractive eccentric globule, prob- 

 ably escaping through a pore formed within the apical collarette of 

 teeth; resting spores not observed. 



In rotting plant tissues, in company with Cladochytrium tenue, France. 



Although the species is obviously distinct from other members of 

 Cladochytrium by reason of the ornamentation of the sporangium, some 

 features of it are puzzling. De Wildeman has shown in Figure 14 an 

 empty sporangium within which are three empty saclike structures. 

 These he thought belonged to a parasitic organism. Over half the figures 

 of mature sporangia shown have "vacuoles" within them which in 

 some cases approximate in size and shape the empty sporangia of the 

 parasitic organism. Earlier monographers have doubted the validity of 

 the species. This is not questioned here, yet the possibility that the con- 

 cept is based on parasitized and hypertrophied specimens of Phlyctochyt- 

 rium planicorne — found in the same habitat — cannot be entirely ex- 

 cluded. 



? Cladochytrium irregulare de Wildeman 

 Ann. Soc. Beige Micro. (Mem.), 19: 91, pi. 3, figs. 1-13. 1895 



A fungus parasitic in aquatic grasses with irregular tubular sporangia 

 which resemble those of Mitochytridium and which are 200-235 (?) \l 

 long by 15-40 \x wide and borne on a branched rhizoidal system has 

 been called a species of this genus by de Wildeman {he. cit.). No zoo- 

 spores were observed, and its affinities are in doubt. 



? Cladochytrium polystomum Zopf 

 Nova Acta Acad. Leop.-Carol., 47: 234, pi. 21, figs. 1-11. 1884 



Sporangia spherical or fusiform, intercalary, originating as spindle- 

 shaped enlargements on the vegetative system, forming from one to six 

 long irregular discharge tubes; vegetative system extensive, branched, 

 slender, rhizoidal; zoospores spherical with a brownish-orange oil 

 globule; resting spores not observed. 



