CHYTRID1ALES 285 



Rhizophydium zoophthorum (Dang.) Fischer 



Rabenhorst. Kryptogamen-F!., 1 (4): 94. 1892 

 (Fig. 17 O, p. 228) 



Chytridium zoophthorum Dangeard, Bull. Soc. Bot. France, 34:xxii. 

 1887; Le Botaniste, 1 :58, pi. 3, figs. 10, 21. 1889. 



Sporangia sessile, often in clusters, ovoid or somewhat pyriform, 

 with a prominent apiculus, 20-25 jjl long by 15—17 ^ in diameter, wall 

 thin, smooth, colorless; rhizoids extensive, richly branched, arising 

 as secondary branches from a main axis ; zoospores ovoid, 3 jjl (long?), 

 with dense granular plasma, a slightly refractive colorless basal glob- 

 ule, and a flagellum 30 \x in length, escaping through a narrow pore 

 formed at the tip of the apiculus; resting spore not observed. 



Parasitic on adults and eggs of rotifers, Dangeard {he. cit.), France; 

 liver-fluke eggs, coll. J. Bayley Butler, Sparrow (1943: 196), Ireland; 

 rotifer eggs, Karling (1946b: 10, pi. 2, figs. 43-45), Brazil. 



The habitat, ovoid sporangium with prominent apiculus, and richly 

 branched rhizoidal system are distinctive features of this species. 

 The living material from Ireland, on liver-fluke eggs, was kindly sent 

 for examination by Professor Bayley Butler, of University College, 

 Dublin, in 1933. Other of the eggs were infected by Catenaria and a 

 fungus similar to Rhizophydium globosum. The thalli of the present 

 species frequently formed dense clusters at the operculate apex of the 

 fluke eggs. A similar gregarious habit was noted by Dangeard on 

 rotifer eggs. 



Rhizophydium apiculatum Karling 



Amer. J. Bot., 33: 331, figs. 33-37. 1946 

 (Fig. 18 H, p. 286) 



"Thalli numerous, up to 26 on a host. Sporangia h> aline, smooth, 

 fairly thick-walled, pyriform (6-10 x 14-18^), slightly obclavate, 

 flattened, or anatropous with one to three prominent exit papillae 

 which may often become extended to short tubes, 4 x 6 \l long. Zoo- 

 spores spherical, 3-3.5 \l, with a small refractive globule. Rhizoidal 

 system richly branched. Resting spores hyaline, smooth, spherical 

 (8-12 (x), pyriform (10 x 14 \l), often apiculate; containing a large 



