CHYTRIDIALES 579 



hyaline refractive body, 2.5-2.8 [jl diam., flagellum 30-34 \x long. Per- 

 sistent zoospore cyst usually thick-walled, bearing 1-20 simple or branch- 

 ed, long (30-300 \x) or short (15-12 [i), cylindrical setae, up to 3 jjl 

 diam. Rhizoids typically constricted at intervals and usually branching 

 dichotomously and sometimes extending for a distance of 320 [x; rhi- 

 zoidal segments predominantly cylindrical (7 10x20-42 ji.) and thick- 

 walled at maturity. Resting spores spherical (19-25 (jl), oval (15-20 X 

 17-30 [x), oblong (20-24 x 30-32 jx), occasionally lobed or constricted 

 with a smooth, 2-3 \x thick, dark, reddish-brown wall and coarsely 

 granular refractive content; germination unknown" (Karling, loc. cit.). 



Saprophytic in cellulosic substrata, United States. 



In thallus development, the rudiments of the rhizoidal system were 

 laid down first, and succeeded by that of the sporangium. 



IMPERFECTLY KNOWN GENUS OF THE CHYTRIDIACEAE 



? HAPLOCYST1S Sorokin 



Bull. Soc. Nat. Kazan, 4(3): 11. 1874 



Thallus epibiotic, monocentric, obpyriform, with a short narrow 

 stalklike base, apparently without a vegetative system, superficially 

 attached to the substratum, the contents divided by successive cleavage 

 into thirty-two parts which rotate within the operculate sporangium 

 and conjugate in pairs; swarmers (planozygotes) biflagellate, emerging 

 upon the dehiscence of a broad operculum, movement hopping; resting 

 stage not observed. 



A monotypic marine genus on submerged wood. 



? Haplocystis mirabilis Sorokin 

 Bull. Soc. Nat. Kazan. 4 (3)- 1 1, pi. I, figs. 44-55. 1874 

 Sporangium 117 [x high, wall thin, smooth, swarmers sixteen, spher- 

 ical, 11 [x in diameter, with a refractive globule, upon germination 

 enlarging to form a new sporangium. 

 On wood, Italy (Venice). 



A fungus with such a remarkable life history is not improbable, but 

 it certainly needs validation. 



