CHYTRIDIALES 591 



Resting spores spherical (12-22 u,), oval (15-18 x 20-25 fx), with a 

 large refractive globule surrounded by numerous smaller ones, wall 

 smooth, 1.5-2 ja thick, faintly yellowish-brown in color; functioning as 

 prosporangia in germination" (Karling, be. cit.). 



Saprophytic in decayed vegetable debris, Brazil; soil, Reinboldt 

 (1951 : 178), Germany; vegetable debris, cellulosic substrata, Shen and 

 Siang (1948: 186), China; bleached grass leaves from soil, Karling 

 (1948c: 510), R. M. Johns (coram.), (Texas) United States. 



Disposition of this species is difficult. Karling (1945a) points out 

 clearly that the typical method of discharge is by a slightly sunken (and 

 presumably endo-) operculum. Sometimes, however, a true operculum 

 is formed. Although Shen and Siang (1948) mention an operculum, 

 they do not indicate whether it is a true operculum or an endooperculum. 

 We have studied a form which in every respect but one corresponds 

 exactly with this species. In it no operculum of any kind whatever is 

 formed. The resolving of this puzzle awaits further study. Meanwhile, 

 since some true opercula were observed in the type material, the present 

 species is retained tentatively in Nowakowskiella. 



Nowakowskiella atkinsii Sparrow 



J. Wash. Acad. Sri., 40: 52, figs. 25, 26. 1950 



(Fig. 36 A, p. 590) 



Thallus extensive, much branched, bearing occasional irregular swell- 

 ings and rarely very large (35-40 u. by 18-25 \x) setigerous one-or two- 

 celled turbinate organs; sporangia at the tips of more or less elongated 

 branches, rarely intercalary, predominantly spherical and 13-20 [i in 

 diameter or somewhat pyriform, often apophysate; the wall bearing a 

 variable number of somewhat thickened flexuous setae, 9-16 y. long; 

 zoospores slightly ovoid, 5 by 3 jx with a single hyaline globule and 



Explanation of Figure 36 



A. Nowakowskiella atkinsii Sparrow. B. Septochytriwn plurilobum Johan- 

 son; thallus showing resting spores and sporangia. C. Nowakowskiella 

 elongata Karling. D-F. Nowakowskiella hemisphaerospora Shanor ; stages 

 in development of resting spore. 



(A, after Sparrow, 1950; B, after Johanson, 1943; C, after Karling, 1944b; 

 D-F, after Shanor, 1942b) 



