CHYTRIDIALES 403 



Sporangium terminal, ellipsoidal, with a sharp lateral beaklike dis- 

 charge tube; vegetative system rudimentary, the few cells bearing 

 lateral protrusions of variable extent; zoospores not observed; resting 

 spore not observed. 



In young plants of Oedogonium sp., Asiatic Russia. 



IMPERFECTLY KNOWN GENUS OF THE PHLYCTIDIACEAE 



? ACHLYELLA Lagerheim 



Hedwigia, 29: 144. 1890 



(Fig. 19 F, p. 318) 



Thallus epi- and endobiotic, monocentric, the epibiotic part consist- 

 ing of the rudiment of the sporangium, the endobiotic part a broad 

 rounded haustorium without rhizoids; sporangium inoperculate ; zoo- 

 spores emerging as nonfiagellate individuals, encysting in a group at the 

 orifice of the sporangium, emerging from the cyst through a minute 

 pore, flagellation of the motile spores unknown; resting spore not 

 observed. 



On pollen of Typha. 



Because of the lack of information on the development of the thallus 

 and on the flagellation of the spore the relation of the genus to the 

 chytrids is problematic. 



? Achlyella flahaultii Lagerheim 

 Hedwigia, 29: 144, pi. 2, figs. 5-7. 1890 

 Sporangium inoperculate, sessile, narrowly pyriform, with a some- 

 what prolonged erect or bent apex, wall slightly thickened, colorless, 

 smooth; haustorium broad, knoblike, thin-walled; zoospores discharged 

 through a pore formed at the apex of the sporangium, cysts spherical ; 

 otherwise unknown. 

 On pollen of Typha, France. 



RHIZIDIACEAE 



Thallus predominantly interbiotic, monocentric, eucarpic, consisting 

 of a well-developed, frequently extensive, rhizoidal system, of which 



