CHYTRIDIALES 123 



Differing from Olpidium in the structure of the zoospore and, to a 

 lesser degree, in the lack of the characteristic chytridiaceous fat glob- 

 ules in the contents of the developing sporangium. 



Olpidiomorpha pseudosporae Scherffel 

 Arch. Protistenk., 54: 515, pi. 28, figs. 7-8. 1926 

 Sporangium more or less spherical or broadly ovoid, 8-14 [x in diam- 

 eter, with a single long slender discharge tube 3 \i in diameter, wall 

 thin, smooth, colorless; zoospores ovoid, 3-4 [X long by 2 jx in diam- 

 eter, slightly attenuated posteriorly, plasma dense, homogeneous, 

 with an anterior circlet of strongly refractive granules and a small 

 lateral basal vacuole, flagellum from four to five times as long as 

 body, emerging individually and at once swimming away, movement 

 smooth, gliding in a zigzag line; resting spores not observed. 



In zoocyst of Pseudospora leptoderma, living in Vaucheria sp., 

 Hungary. 



NUCLEOPHAGA Dangeard 



Le Botaniste, 4: 214, 1894-95 

 (Fig. 12 A, p. 124) 



Thallus endobiotic, within the nucleus of the host, holocarpic; 

 sporangium inoperculate, formed from the walled thallus, filling the 

 nuclear cavity, spores simultaneously formed, set free upon the dis- 

 integration of the host body. 



A genus of uncertain relationships. 



Nucleophaga amoebae Dangeard 

 Le Botaniste, 4: 214, figs. 1-5. 1894-95. 



From one to five sporangia in the hypertrophied nucleus of the 

 amoeba; spores spherical, up to one hundred in a sporangium. 



In Amoeba verrucosa, France. 



Since the vegetative body of the organism did not ingest the solid 

 particles of the host, Dangeard considered Nucleophaga amoebae a 

 chytrid allied to Sphaerita. The vital activities of the host were not 

 affected until the time of sporulation of the parasite. The host then 

 disintegrated, allowing the spores to be dispersed. 



