CHYTRIDIALES 163 



? Pleotrachelus olpidium H. E. Petersen 



Oversigt. Kgl. Danske Vidensk. Selskabs. Forhandl., 1905 (5): 455, 



fig. Ill, 7-9 



Sporangia one or more in a host cell, not filling the lumen nor caus- 

 ing hypertrophy, regularly more or less spherical, with a smooth color- 

 less wall which does not react to chlonodide of zinc, 9-30 \x in diam- 

 eter, with from one to three discharge tubes 9-24 [i. long; zoospores 

 not seen; resting spore borne singly and loosely in a structure not dif- 

 fering in shape or size from the zoosporangium, with a smooth thicken- 

 ed wall. 



In Ectocarpus confervoides, coll. Borgesen, Petersen (Joe. cit.), Faroe 

 Islands; Ectocarpus sp., E. confervoides, Furcellaria (coll. K. Rosen- 

 vinge), Akinetospora, Petersen (be. cit.), Polysiphonia sp., Pylaiella 

 littoralis, Sparrow (1934c: 19, pi. 4, figs. L, N), Denmark; Ecto- 

 carpus penicilliatus, Aleem (1953:6, figs. 5-6), Sweden; Spermatoch- 

 nus paradoxus, J. Feldmann (1954: 132), France. 



? Pleotrachelus paradoxus H. E. Petersen 



Oversigt. Kgl. Danske Vidensk. Selskabs. Forhandl., 1905 (5): 459, 



fig. IV, 7-8 



Sporangium of variable shape, frequently irregular, sometimes more 

 or less spherical, sometimes oblong, one or several in each host spo- 

 rangium, when occurring singly filling the host structure, wall color- 

 less, thin, smooth, turning violet with chloriodide of zinc, with one 

 or several discharge tubes passing through the discharge pores of the 

 host sporangium, causing thickening of the host wall; zoospores not 

 observed. 



In sporangia of Rhizophydium discinetum, coll. F. Borgesen, Norway. 



? Pleotrachelus radicis de Wildeman 



Ann. Soc. Beige Micro. (Mem.), 17: 23, pi. 3, figs. 20-25. 1893; ibid., 19: 70, 



pi. 2, figs. 23-35. 1895 



Sporangium spherical or ovoid, wall colorless or slightly yellow, 

 with a large number of conical or tubular, sometimes irregular, dis- 

 charge tubes; zoospores and resting spore not observed. 



