334 AQUATIC PHYCOMYCETES 



rarely ellipsoidal, 20-38 u. long by 15-20[j. in diameter, wall smooth, 

 thin, colorless; endobiotic part consisting of an ovoid subsporangial 

 swelling with a few scarcely visible rhizoids; zoospores about 3 u, 

 in diameter, emerging through a broad apical pore with an irregular 

 margin; resting spore unknown. 



On Chaetophora elegans, coll. Goffart, Belgium. 



No information is given on the number of flagella on the zoospores. 



Phlyctochytrium biporosum Couch 

 J. Elisha Mitchell Sci. Soc, 47: 254, pi. 17, figs. 52-65. 1932 



Sporangium sessile, spherical or ovoid at first, becoming truncated 

 and angular in outline upon the formation of two broad oppositely 

 placed apical sessile or slightly elevated discharge papillae, 10-12 [i 

 high by 8—13 jx in diameter, wall delicate, disappearing soon after 

 zoospore discharge, smooth, colorless; rhizoid somewhat broad, un- 

 branched or branched, slightly expanded immediately beneath the 

 host wall; zoospores spherical or somewhat ovoid, 2-2.6 fj. in diam- 

 eter, with a minute refractive basal granule and a long fiagellum, 

 emerging through two pores formed upon the deliquescence or burst- 

 ing of the two discharge papillae, movement amoeboid or swimming; 

 resting spore not observed. 



On Vaucheria sp., Bumilleria sp., Oedogonium sp., Couch (he. cit.), 

 Spirogyra sp., Sparrow (1933c: 522, fig. I, 19-20), United States; 

 (?) Spirogyra sp., Sparrow (1936a: 443, fig. 3 m-p), Great Britain 

 (see Rhizophydium haynaldii, p. 264); pine pollen, Gaertner (1954b: 

 21), Egypt, Northwest Africa, Equatorial East Africa, South 

 Africa; Gaertner (op. cit., p. 41), Sweden. 



The very slight development of the subsporangial apophysis, which 

 in some cases is completely lacking, makes the generic disposition 

 of the species difficult. Couch could not be certain that the rhizoid 

 branched, but such branches have been observed by Sparrow (1933c). 

 The zoospores of Sparrow's fungus differed from Couch's in having 

 a centric globule. Sparrow has tentatively referred to this species a 

 fungus found on Spirogyra in Great Britain which has sporangia es- 

 sentially like those of Couch's fungus save that the papillae are more 



