144 AQUATIC PHYCOMYCETES 



Olpidium rhizophlyctidis Sparrow 

 Mycologia, 40: 449, figs. 7, 8, 12, 14, 18, 19. 1948 



Sporangia spherical or ellipsoidal, 25-50 (jl long by 12-45 u, in diam- 

 eter, hyaline, smooth-walled, with a single discharge tube which 

 protrudes through the host wall; zoospores numerous, spherical, about 

 2 \x in diameter, without a conspicuous globule, posteriorly uniflagel- 

 late, movement an erratic hopping interspersed with periods of swim- 

 ming; resting spore spherical, 12-20 fx in diameter, faintly brown, 

 apparently asexually formed, with a smooth wall about 2 \i thick, 

 contents with a large fat droplet, germination not observed. 



Parasitic in thalli, sporangia, and resting spores of Rhizophlyctis 

 spp., Bikini, Eniwetok, and Rongelap atolls, Marshall Islands, 

 Sparrow {Joe. cit.); Sparrow (1952a: 35), Cuba. 



Olpidium gregarium (Nowak.) Schroeter 



Kryptogamenfl. Schlesien, 3(1): 182. 1885 

 (Fig. 13 F-G, p. 136) 

 Chytridium gregarium Nowakowski, in Cohn, Beitr. Biol. Pflanzen, 2: 

 77, pi. 4, fig. 2. 1876. 



Sporangia spherical, ovoid, ellipsoidal, or irregularly saclike, the 

 spherical ones 30-70 y. in diameter, the ovoid and ellipsoidal ones 

 18-35 a, long by 17-32 u. in diameter, with a single short broad papilla 

 7-10 fj. in diameter which protrudes through the wall of the egg, wall 

 thin or slightly thickened, smooth, colorless; zoospores spherical, 

 2.5 4 ;x in diameter, with a single eccentric refractive globule and a 

 long flagellum, emerging through a pore formed at the tip of a nearly 

 sessile or slightly protruding discharge tube and either forming a 

 temporary compact mass surrounded by a quickly evanescent slime 

 film or swimming directly away, movement swimming and amoeboid; 

 resting spore sometimes lying loosely in a spherical containing struc- 

 ture, spherical, brownish, thick-walled, the wall up to 6 a thick, smooth 

 or with faint striations, 15-20 [i in diameter, containing a large globule, 

 germination not observed. 



Parasitic on rotifer eggs. Nowakowski (he. cit.), E. J. Butler (1907: 

 136, pi. 8, figs. 13 IS), coll. (?) Hieronymus, Schroeter (1885: 182), 

 Germany; eggs of Brachionus sp., adults of Euchlanis sp., Tokunaga 



