CHYTRIDIALES 417 



onion skin, Karling (Joe. cit.), Brazil ; cockroach wings, chitin, Karling 

 (1948c: 509), United States. 



See the comments on this species under Rhizidium mycophilum (p. 410). 



Rhizidium braziliensis Karling 

 Amer. J. Bot., 31 : 254, figs. 1-19, 23-30. 1944 



"Sporangia extramatrical, hyaline, smooth, spherical (10-40 fi.), pyri- 

 form (8-40 X 12-50 \x), oval and slightly anatropous ( 1 5-20 x 18-30 [jl), 

 sometimes quite irregular and slightly stellate; usually apophysate, 

 apophysis intra- or extramatrical, almost spherical (4-10 \x), oval or 

 fusiform; sporangia opening by one to four conspicuous hyaline exit 

 papillae arising from the surface of the sporangia or situated at the 

 ends of one or more long (3-8 x 15-60 (i.) tubes. Rhizoidal system 

 usually intramatrical, main axis up to 6 u. in diam., extending from 50 

 to 220 [i, usually branching more or less dichotomously and tapering 

 abruptly. Zoospores oval to slightly elongate, 3-3.5 x 5-5.5 \x, usually 

 with one relatively small refractive globule lying at one side and slightly 

 toward the base; emerging in a globular mass which becomes enveloped 

 by a vesicle in which the individuals swarm for several minutes before 

 breaking out and swimming away; flagellum 33-35 [x long. Resting 

 spores extramatrical, hyaline, usually apophysate, spherical (10-25 \x), 

 oval (10 x 14-20 x 23 fx), or oblong and slightly flattened with one 

 to several large refractive globules; wall 1.5-2 (x thick, warty, horny or 

 spiny; horns or spines varying from a few to more than fifty in number, 

 short or up to 4 [x high and tapering abruptly. Resting spores functioning 

 as prosporangia in germination, giving rise to thin-walled sporangia on 

 their surface" (Karling, loc. cit.). 



Saprophytic in fragments and exuviae of insects, in water, Brazil. 



Rhizidium laevis Karling 



Amer. J. Bot., 31 : 254, figs. 20-22. 1944 



"Sporangia extramatrical, hyaline, smooth, spherical (5-50 fx), or 

 oval and slightly anatropous (6 x 8-20 x 30 \i), irregular and somewhat 

 stellate with one to three exit papillae; apophysate, apophysis oval, 

 fusiform and almost spherical, 4-10 [x in diam. Rhizoids intramatrical, 



