388 AQUATIC PHYCOMYCETES 



and transference of material took place at a very early stage in thallus 

 development. 



Dangeard (1886a) noted that the sporangium alone, or the sporangium 

 and the apophysis, may occasionally be epibiotic. 



Diplophlyctis amazonense (Karhng), comb. nov. 

 Nephrochytrium amazonensis Karling, Mycologia, 36: 352, figs. 1-28. 1944. 



"Thallus monocentric, usually intramatrical; consisting of a sporan- 

 gium or resting spore subtended by an apophysis from which arises an 

 extensive, richly branched rhizoidal system. Sporangia hyaline, smooth, 

 pyriform, 12-30 x 50-140 jx, almost spherical, 10-60 [L in diam., obcla- 

 vate, flattened and often somewhat kidney-shaped with a short, 5 x 10 

 [i, or an elongate, 5-7 x 20-130 \x, tapering exit tube. Tip of tube 

 swelling and softening to form a plug of hyaline material; operculum 

 subsequently developed down in exit tube; operculum shallow saucer- 

 shaped, deeper bowl- or cup- and occasionally somewhat cone-shaped, 

 4-7 [i in diam. Zoospores emerging fully developed and forming a 

 globular mass at the exit orifice before dispersing; spherical, 5-6.5 \i, 

 with a large refractive globule and a 35-38 \l long flagellum. Apophysis 

 oval, 5-12 x 8-22 [x, flattened, obpyriform, or almost spherical. 

 Rhizoidal system arising from base of apophysis, extending over a 

 radius of 80-400 \x, main axis up to 8 \x in diam., richly branched. 

 Resting spores usually oval and somewhat bean-shaped, 20-28 x 30-40 

 (X, almost spherical, 15-35 \x, and sometimes irregular; content coarsely 

 granular and brown; wall dark brown, 2-3 \x thick, usually spiny, 

 sometimes verrucose or covered with numerous short setae, rarely 

 smooth; functioning as prosporangia in germination" (Karling, he. 

 cit.). 



Saprophytic in decaying vegetable debris, Karling (Joe. cit.), Brazil; 

 on onion skin and cellophane from soil, Karling (1948c: 509), United 

 States. 



In view of the variation in sequence of thallus development in 

 Diplophlyctis and Haskins' (1950) subsequent observations on the 

 inconstancy of formation of endoopercula in D. sexualis, placement 

 of the Brazilian species in this genus seems justified. Indeed, prior 



