170 AQUATIC PHYCOMYCETES 



a posterior llagellum, escaping through a small pore resulting from 

 the dissolution of the papilla; resting spore formed in the sporangium 

 o\' the host, spherical, somewhat thick-walled, brownish (?), covered 

 with very short tenuous spines. 



Parasitic for the most part in the terminal segments (sporangia) of 

 [podachlya brachynema, France. 



Plants of Araiospora occurring in the same tufts as the Apodachlya 

 were not infected by the zoospores of Rozella apodyae-brachynematis. 

 The spines on the resting spore are noticeably shorter than those of 

 R. rhipidii-spinosi. 



Rozella cuculus (Butler) Sparrow 



Mycologia, 30: 377. 1938 



Pleolpidium cuculus Butler, Mem. Dept. Agr. India, Bot. Ser., 1: 125, pi. 

 7, figs. 22-25. 1907. 



Sporangium spherical, subspherical, or pyriform, formed in the spo- 

 rangium of the host or in pronounced intercalary swellings of the hy- 

 phae, 19.2-24 u. in diameter, with a single papilla; zoospores obclavats, 

 clavate, or ovoid, the flagellum emerging from the broader end; resting 

 spore spherical, single, free in the sporangium or intercalary swelling 

 of the host, 1 2 1 8 ix in diameter, with a smooth pale-yellow somewhat 

 thickened wall, germination not observed. 



Parasitic in sporangia of Pythium intermedium, Butler {be. cit.), 

 Ireland, France; hyphae of Pythium monospermum, Tokunaga (1933b: 

 82, pi. 5, fig. 12), Japan. 



Pleolpidium tuber culorum Vuillemin (1909) should perhaps be in- 

 cluded under this species, since it differs from Butler's fungus only in 

 ha\ing slightly larger and fewer zoospores and somewhat larger resting 

 spores (17.5 23 by 15.4 20 u.). It was found in France parasitic in the 

 sporangia of Pythium. 



Chytridium simulans Dangeard (1896-97: 21, fig. 1) occurring in ter- 

 minal or lateral swellings on Pythium, may be referable to Rozella 

 cuculus. Resting spores, however, were not observed. The species is 

 listed as a synonym of R. cuculus by Karling (1942b: 198). 



