416 AQUATIC PHYCOMYCETES 



quescence of a single usually terminal discharge papilla; resting spore 

 not observed. 



Saprophytic in integuments of Phryganeidae, Denmark; Chironomi- 

 dae, Ephemerida, United States. 



Rhizidium ramosum differs from R. mycophilum in possessing a very 

 short, rather than an elongated, subsporangial main axis. This termi- 

 nates in a profusely branched rhizoidal system. A further variation is 

 found in the peculiar refractive nodules which occur on some of its 

 sporangia. Certain slight differences noted between the Danish and the 

 American material do not, at least for the present, seem of sufficient 

 import to separate the two as distinct species. 



Rhizidium nowakowskii Karling 



Amer. J. Bot., 31: 255, figs. 31-33, 69-72. 1944 



(Fig. 25 E-G, p. 411) 



Rhizidium mycophilum Braun, sensu Nowakowski, in Cohn, Beitr. Biol. 

 Pflanzen, 2: 87, 1876. 



"Sporangia straight or slightly tilted on the rhizoidal axis, hyaline, 

 smooth, spherical (15-10 \l) pyriform (8 X 10-25 X 35 \x), ellipsoidal 

 or oval (15 x 20-70 x 100 u.), oblong (15 x 28^10 x 90 u.) ; apophysate 

 or non-apophysate, apophysis oval, fusiform or almost spherical; 

 opening by a prominent (3 x 4 \i) hyaline exit papilla. Rhizoidal axis 

 broad, up to 6 [x in diam., and extending 100-300 \l, frequently branched 

 and tapering abruptly. Zoospores spherical, 4-5 [i, with a large (2-2.8 yi), 

 conspicuous, hyaline refringent globule and a 30-35 u. long flagellum; 

 emerging in a globular mass which becomes enveloped by a vesicle in 

 which the individuals swarm for several minutes before breaking out 

 and swimming away. Resting spores hyaline, spherical or ellipsoidal, 

 15-30 [i in diam.; wall double-layered, inner layer smooth, outer layer 

 bearing a felt-like covering of fine long hairs; content finely granular 

 and hyaline with a large refractive globule; functioning as prosporangia 

 in germination and giving rise to sporangia on their surface" (Karling, 

 loc. cit.). 



Saprophytic in the gelatinous envelope of Chaetophora elegans, 

 Nowakowski (1876: 87), Germany; in the slime surrounding bits of 



