466 AQUATIC PHYCOMYCETES 



or their equivalent, it is entirely possible, as suggested by Sparrow 

 (1936a) and later proved correct by Bartsch (1945) in the case of Poly- 

 phagia euglenae, that there are two distinct species involved. From the 

 conflicting evidence concerning pathogenicity, it is also possible that 

 different physiological strains exist. 



? Cladochytrium aureum Karling 

 Bull. Torrey Bot. Club, 76: 298. 1949 



Sporangia terminal or intercalary, oval or citriform, 8-19 by 10-23 

 [x, or subspherical and 8-36 u., without discharge tubes; rhizoidal system 

 delicate, extensive, the narrow part 1.2-3.5 \i in diameter, with septate 

 oval and 6-8 by 9-12 u., fusiform and 5-8 by 10-17 \i, or irregular 

 swellings; zoospores spherical, 5.8-6.2 u, in diameter, with a conspic- 

 uous, 2-2.4 \x in diameter golden-orange to red globule and fiagellum 

 27-29 [j. long; resting spores spherical and 9-17 \x in diameter or oval 

 and 8-12 by 1 1-16 u. or fusiform, germination not observed. 



Saprophytic in vegetable debris, United States. 



The only significant difference between this species, as presented, and 

 Cladochytrium replication is a lack of spines on the resting spore (see 

 discussion under the latter species) and absence of a discharge tube on 

 sporangium. 



Cladochytrium setigerum Karling 

 Bull. Torrey Bot. Club, 78: 38, figs. 1-8. 1951 

 Sporangia commonly intercalary, oval, 11-27 by 19-44 u,, spherical, 

 13.2-28.5 fj., occasionally elongate and constricted, sometimes with a 

 funnel-shaped elongate apophysis, bearing 10-50 simple or branched 

 5.5-30 u. long by 1.7-2.4 \x in diameter setae, with a single conical or 

 hemispherical discharge papilla which is sessile or at the tip of a short 

 tube 7-9 by 14-20 \x long; rhizoidal system extensive, delicate, branched, 

 1.7-2.8 \x in diameter, with a few nonseptate fusiform, elongate, or 

 irregular enlargements 6-10 u, broad by 8-18 \i long; zoospores spher- 

 ical, 3-3.4 [i in diameter, with a minute basal, colorless globule 0.8-1.2 

 [x in diameter and 16-19 \x long fiagellum, upon discharge forming a 

 temporary globular mass at the orifice before swimming away; resting 

 spores not observed. 



