CHYTRIDIALES 311 



cooked striated muscle cells and root tips of various plants. The 

 sporangia may be almost spherical (10—52 pt), slightly depressed, 

 wedge-shaped and somewhat triangular (14 x 29u.-25 x 30 \x), oval 

 and occasionally slightly irregular with 1 to 1 1 exit papillae. The smaller 

 sporangia may often resemble those of R. agile, R. gibbosum, R. 

 rostellatum and Phlyctochytrium bisporum [biporosum]. Resting spores 

 have so far not been found" (Karling, he. eit.). 



? Rhizophydium sp. Scherffel 

 Arch. Protistenk., 53:28, pi. 2, figs. 57-59. 1925. 



Sporangium sessile, upright, pyriform, 8 jjl high by 5 \x in diameter 

 at the base, wall smooth, colorless; endobiotic system not observed; 

 zoospores not observed; immature resting spore ovoid, with a flat- 

 tened base, wall thin, smooth, colorless, contents homogeneous, with 

 one or two large oil droplets, becoming spherical at maturity; con- 

 tributing thalli from one to three, small, somewhat spherical or ovoid, 

 attached directly or by a short copulation tube to the base of the re- 

 ceptive thallus; other characters unknown. 



On Tribonema bombycina, Hungary. 



Scherffel is not certain that the sporangial stage he observed belonged 

 to the fungus which was forming resting spores. 



? Rhizophydium sp. 



Sporangium sessile, spherical, subspherical, or broadly urceolate, 

 with an apical or subapical papilla, 5.5-10 [i in diameter, wall smooth, 

 thin, colorless; zoospores not observed, apparently emerging through 

 a single somewhat broad apical or subapical pore; rhizoidal part con- 

 sisting of a tuft of poorly developed digitations which arise from a 

 short stout main axis; resting spore epibiotic, spherical, 10 a, in diam- 

 eter, with a thick smooth colorless wall, rhizoids consisting of a tuft 

 of short digitations, germination not observed. 



On Bumilleria sp., Couch (1932:252, pi. 17, figs. 84-87), United 

 States; Spirogyra sp., Sparrow (1936a: 443, fig. 3s), Great Britain. 



Since the discharge of the zoospores has not been observed, the fun- 

 gi of Couch and Sparrow may belong in an operculate genus. Though 



