482 AQUATIC PHYCOMYCETES 



celioid, branched filaments of fairly uniform diameter; zoosporangia 

 terminal, extramatrical, occurring singly or in clusters. Zoospores 

 posteriorly uniflagellate; resting spores doubtful or unknown. 



Other than Johanson's description, no figures or further account of 

 this organism have been published. At a meeting of the Mycological 

 Society of America in New York (1949), both Miss Johanson and 

 Karling agreed that species of Actinoplanes (Actinomycetes) described 

 at the same sessions by J. N. Couch were entirely similar to Mycel- 

 iochytrium. It is mentioned by Karling (1954b) in connection with a 

 description of an undoubted member of Couch's group. 



? Myceliochytrium fulgens Johanson 

 Torreya, 45: 104. 1945 



"Rhizomycelium delicate and narrow, 1.3-1.7 jjl in diameter without 

 intercalary enlargements. Zoosporangia hyaline and highly refractive 

 with thin, .3-.6 \i walls, sub-spherical, 5.5-8.7 [j., somewhat rectangular 

 and truncate, 6.6-17.5 \i x 10.3-26.2 \i, oval, ellipsoidal, 8.7-20.7 \x, 

 urceolate, 9.6-21.0 \x, broadly pyriform, 6.2-38.5 \l, oblong, irregular, 

 or frequently gibbose; dehiscing by rupture or deliquescence of the 

 sporangial wall. Zoospores usually arranged in linear rows, giving 

 sporangia characteristic appearance, spherical, 1.3-2 \x with a minute, 

 .5 \x refractive globule; flagellum approximately 11 \i long; frequently 

 swarming in sporangium, and emerging singly or in rows as sporangium 

 swells and ruptures. Walls of sporangium and remainder of rhizomyce- 

 lium reacting negatively to cellulose tests" (Johanson, he. cit.). 



Saprophytic on vegetable substrata, chitin, and keratinized substrata, 

 Johanson, (he. cit.), keratinized substrata, onion skin, cellophane, soil, 

 Karling (1948c: 510), United States; Brazil. 



PHYSODERMATACEAE J 



Chytridiaceous fungi forming thalli of two types, one monocentric 

 and consisting of an endobiotic rhizoidal system and an epibiotic thin- 

 walled sporangium, the other polycentric and wholly endobiotic and 



1 The family was first proposed by Sparrow (Mycologia, 34: 113) in 1942, but 

 not diagnosed by him {ibid., 44: 768) until 1952. 



