CHYTRIDIALES 235 



Sporangium 26-50 \l in diameter; on oogonia of Vauche- 



ria R. vaucheriae, p. 275 



On aquatic Phycomycetes, primarily the oogonia and oospores 



R. carpophilum, p. 276 



On nematodes R. vermicola, p. 277 



Sporangium pyriform 



Sporangium wall collapsing and disintegrating immediately after 

 spore discharge 



Rhizoids unbranched; on Mischococcus R. mischococci, p. 278 



Rhizoids richly branched; on Chroococcus R. agile, p. 278 



Sporangium wall persistent after discharge 

 On algae 



Sporangium smooth-walled 



Sporangium with an apical discharge pore 



Primarily on Chlamydomonas R. acuforme, p. 279 



On other algae 



Sporangium small (5-6 \x diameter) ; on Spirogyra 



R. minutum, p. 280 

 Sporangium larger; on various algae 



Sporangium broadly pyriform, imbedded, save for 

 its apex, in the gelatinous sheath of Eudorina 



R. eudorinae, p. 281 

 Sporangium narrowly pyriform, resting on the outer 

 surface of the substratum; on various algae 

 On the gelatinous sheath of Apiocystis R. brauni, p. 282 

 On the surface of the gelatinous sheath of cysts of 

 Cryptomonas or Pandorina, or directly on the 



wall of other algae R. simplex, p. 282 



Sporangium with a subapical discharge pore 

 Pore terminating a short discharge tube; sporangium 

 large (16-20 by 13-18 jj.), apiculate, upright; on 



Oocystis R. pseudodistomwn, p. 283 



Pore not terminating a tube; sporangia small (7-14 by 

 5-9 |x), appearing somewhat tilted; on Tribonema 



R. gramdospontm, p. 283 



Sporangium covered with warts R. verrucosum, p. 284 



On microscopic animals 



Discharge pore apical, single, sessile; on adults and eggs of 



rotifers R- zoophthorum, p. 285 



Discharge pores one to several, terminating tubes 6 \x long; 



on a protozoan R- apicidatum, p. 285 



Sporangium conical, with two to six narrow exit pores, on Netrium 



R. conicum, p. 287 



