CHYTRIDIALES 367 



sporangium and similar to it in shape, wall thick, smooth, colorless, 

 contents with one to many globules. 



Parasitic in the Palmella stage of Chlamydomonas sp. and in immature 

 swarmers within the mother cell, never on moving individuals, Zopf 

 (loc. cit.), Germany; Scherffel (1914), Hungary. 



The organism occurred in epidemic proportions in Zopf's material. 

 De Wildeman (1895a: 71) has referred to this species a fungus on an 

 undetermined alga from Switzerland. No appendicular structure was 

 observed, however, and he rightly suggests the possibility that it may 

 be Rhizophydium simplex. Similarly, Cook (1932a: 139, figs.26-31) has 

 called a fungus found by him on Chlamydomonas in England Rhizidium 

 appendiculatum, but, if the sequence of development described is 

 correctly interpreted, it cannot be referred either to Scherffeliomyces 

 or to Rhizidium. 



RECENTLY DESCRIBED TAXON 1 



Scherffeliomyces leptorrhizus Johns 

 Mycologia, 48: 433, figs. 1-12. 1956 



"Sporangium ovoid or subspherical, 15-26 x 18-27 u, in diameter, 

 wall colorless, attached by a short apical process to a spherical cysto- 

 spore 4-5.5 [j. in diameter; intramatrical portion consisting of a single 

 slender stalk terminated by a tuft of branched isodiametric rhizoids, 

 infrequently with an intramatrical subsporangial vesicle. Zoospores 

 posteriorly uniflagellate, 4-5 (jl in diameter, equipped with a single 

 eccentric oil globule, fully formed in the sporangium, discharged at 

 maturity through the deliquescence of a single subapical papilla ^merg- 

 ing in a mass and remaining briefly motionless at the orifice, the mass 

 soon dispersing as the zoospores assume motility; resting spores ovoid, 

 with a terminally attached cystospore, 10-15 x 22-27 jjl, with a thick 

 wall, similar to the sporangia in morphology and development, germi- 

 nation not observed" (Johns, loc. cit.). 



Parasitic on Zygnema sp., United States. 



1 Not included in the key. 



