470 AQUATIC PHYCOMYCETES 



presence of numerous granules rather than a single globule in the 

 zoospore mark it as distinct. 



RECENTLY DESCRIBED TAXON J 



Cladochytrium aurantiacum Richards 

 Trans. Brit. Mycol. Soc, 39: 264, figs. 1-3. 1956 



Sporangia generally spherical to subspherical, 18-24 u. in diameter 

 (usually about 22 u.), irregularly shaped when occurring within the 

 narrow cells of substratum, with a narrow discharge tube 8-12 u. long, 

 contents colorless when young, when maturing becoming shot through 

 with reddish-golden or orange globules, proliferating ; rhizoidal system 

 profusely developed, about 2 \i broad with few irregular swellings and 

 once or twice septate turbinate cells, 10-20 \± in diameter with hyaline 

 globules in the contents ; zoospores spherical, 6-7 \i in diameter with a 

 large (3.7-4.2 [i in diameter) spherical eccentric orange globule and long 

 posterior flagellum, escaping upon the deliquescence of the tip of the 

 discharge tube and forming a motionless cluster before swimming away; 

 resting spore not observed. 



In fragments of leaves, stems, and roots of Avena and Triticwn, 

 Great Britain. 



Said to differ from Cladochytrium replicatum and C. aureum by the 

 larger size of the parts, of the zoospores (especially their globule), and 

 of the colorless turbinate cells. 



IMPERFECTLY KNOWN SPECIES OF CLADOCHYTRIUM 2 



? Cladochytrium cornutum de Wildeman 



Ann. Soc. Beige Micro. (Mem.), 20: 59, pi. 3, figs. 1-22. 1896 



Sporangia formed extramatrically, subspherical or reniform, apophy- 

 sate, not separated from the vegetative system by a cross wall, with a 

 crown of from three to seven coarse plain teeth; rhizoidal system 



1 Not included in the key. 



2 For a discussion of certain shell-boring organisms supposedly belonging to 

 this genus see pp. 472-473. 



