820 AQUATIC PHYCOMYCETES 



? Eurychasma sp. Kobayasi and Ookubo 

 Bull. Nat. Sci. Mus. (Tokyo), (N.S.), 1 (2) No. 35:70, fig. 9. 1954 



"Zoosporangium endobiotic at first, gregarious in host-cell, then 

 protruding from the distended host wall and occasionally becoming 

 partly extramatrical by the collapse of the latter, ellipsoid, subglobose 

 or pyriformed, 25-50 u, in diameter, hyaline, thin-walled, with 5-10 

 distinctly protruding papillae, tip of which becoming perforated at 

 maturity by the dehiscence of wall. Rhizoid none. Zoospores not 

 swimming in the sporangium, without flagella, after escape encysting 

 in a loose group at the orifice of papilla. Cysts globose, not angular. 

 Secondary zoospores not observed. Resting spore endobiotic, spheroid, 

 about 50 [j. in diameter, hyaline, thick-walled, further development not 

 observed" (Kobayasi and Ookubo, he. cit.). 



On Bryopsis sp., Japan. 



This unnamed species resembles Eurychasmidium in the behavior of 

 its zoospores and Eurychasma in being partly intramatrical and partly 

 extramatrical. It differs from Eurychasma dicksonii in having more 

 numerous discharge papillae. If the endobiotic resting spore really 

 belongs to the fungus, as seems probable, and if the relationship of the 

 zoospores to either of the aforementioned genera is proved, then this 

 will be one of the few instances in which resting structures have been 

 found in marine members of the Ectrogellaceae. 



EURYCHASMIDIUM Sparrow 



Biol. Bulletin, 70: 241. 1936 

 (Fig. 62, p. 821) 



Thallus endobiotic, plasmodial, holocarpic, without a specialized 

 vegetative system, completely or almost filling the distended host cell; 

 sporangium with many discharge tubes which pierce the host wall; 

 zoospores formed within the sporangium, biflagellate, encysting near 

 the sporangium after discharge, ultimately emerging as motile swarmers ; 

 resting spore not observed. 



Parasitic in marine Rhodophyceae. 



The precise method of entrance of the fungus into the host cell is not 



