CHYTRIDIALES 415 



Sporangium spherical, ellipsoidal, ovoid, or pyriform, 12-24 \x in 

 diameter, wall thin, smooth, colorless ; rhizoids well developed, several 

 millimeters in extent, much branched, strongly polyphagous, generally 

 arising as branches of a clavate main axis; zoospores spherical or ellip- 

 soidal, 2.7-4 \l in diameter, with a strongly refractive globule and a 

 flagellum, discharge not described; resting spore spherical or broadly 

 ellipsoidal, 9-16 \x in diameter, walls thick, the outer layer gelatinous, 

 yellowish, the inner golden brown, refractive, apparently asexually 

 formed on a rhizoidal system like that of the sporangium, contents 

 coarsely granular with a lateral vacuole (globule?), germination not 

 observed. 



On diatoms from a salt pool, Zopf (loc. cit.), Germany; possibly 

 also on desmids attacked by Rhizophydium globosum, Serbinow (1907: 

 161), Finland. 



Minden (1915:375) retained this fungus in Rhizophlyctis, but the 

 presence of a pronounced central rhizoidal axis marks it as a species of 

 Rhizidium. Serbinow's record is to be considered doubtful until further 

 investigations indicate that the fungus, which inhabits salt pools, can 

 also live in fresh water. 



Rhizidium braunii was the first species described by Fischer as repre- 

 sentative of his new genus, Rhizophlyctis. Since, however, Rhizidium in 

 the sense of Braun (not Fischer) was also included in Rhizophlyctis, the 

 present species should have been referred to it when, subsequently, 

 Braun's genus was reestablished in its original sense by Schroeter 

 (1893:79). 



Rhizidium ramosum Sparrow 



Proc. Amer. Phil. Soc, 78 (1): 44, pi. 2, figs. 8-13, pi. 4, fig. 1. 1937 



(Fig. 25 I-J, p. 411) 



Sporangium globose or rarely ellipsoidal, 20-45 u. in diameter, wall 

 slightly thickened, colorless, often bearing several irregular refractive 

 protuberances ; with a short basal main axis from which arises a system 

 of stout branching rhizoids; zoospores ellipsoidal, 6 \i long by 4 [x in 

 diameter, with a lateral colorless globule and a single posterior flagellum, 

 emerging from the sporangium in a compact column after the deli- 



