CHYTRIDIALES 467 



Saprophytic on cellulose substrata, soil, United States. 



As Karling {loc. cit.) implied, this inoperculate species is an almost 

 exact counterpart of the operculate Nowakowskiella atkinsii Sparrow 

 (p. 591). Although he did not regard the septate setigerate turbinate 

 cells as such but as incipient sporangia (and so understood here), they 

 are exactly like those in N. atkinsii. Mention of them is not included in 

 the compiled species description, which is drawn both from Karling's 

 Latin diagnosis and his English text. 



Cladochytrium crassum Hillegas 

 Mycologia, 33: 618, figs. 1-40. 1941 



"Rhizomycelium well developed, extensive, coarse, with numerous 

 intercalary, non-septate, fusiform to globose swellings 3.85 x 15-18 x 

 25 [i, the tenuous portions as little as 1.5 [x in diameter, with trabeculae. 

 Rhizoids 0.5 fx to 1.1 [x in diameter originating at various places along 

 the rhizomycelium. Zoosporangia terminal or intercalary, seldom pro- 

 liferating, non-apophysate, variously shaped, commonly spherical to 

 slightly pyriform, 1 1 x 20-30 x 43 jx. Exit tube occasionally to 27 x 74 

 [x, papilla or pore, usually single, deliquescent. Zoospores delimited 

 within zoosporangium and emerging in a non-motile mass enveloped 

 in slime, which remains at the mouth of the exit tube a few minutes 

 before the zoospores become active and swim away. Zoospore hyaline, 

 spherical to slightly pyriform, occasionally amoeboid, 4.9-6 \x in diam- 

 eter with a clear highly refractive globule 2-2.75 fx in diameter, posterior 

 flagellum 25-35 ;x, swimming rapid and darting. Resting spore spherical 

 (9.35-23 (x diameter) to fusiform (10 / 26 ;x-14.8 23.1 ;x), wall 

 1.5 (x thick, light brown in color, germination unknown"' (Hillegas, loc. 

 cit.). 



Saprophytic on decaying vegetation, Hillegas {loc. cit.), in rotting oat 

 leaves, onion skin and cellophane, moist soil, Karling (1941b: 108; 

 1942c: 620; 1948c: 509), United States; vegetable debris, Karling 

 (1945a: 34), Brazil. 



Karling (1945a: 34) reported that the resting spores germinate after 

 a dormant period of seven weeks. Some functioned directly as sporangia, 

 whereas others produced a sporangium external to the spore. 



