CHYTRIDIALES 139 



Kobayashi and Ookubo (1954b: 573, fig. 16), Japan; Cosmarium sp., 

 Sparrow and Barr (1955: 554), United States. 



Fischer and others after him consider the distinctive constriction 

 characteristic of this species to be brought about by conditions imposed 

 upon the sporangium by the shape of the host cell. Scherffel, how- 

 ever, has found such constricted sporangia lying wholly within one 

 semicell of the desmid. Furthermore, the posteriorly uniflagellate zoo- 

 spores observed by Scherffel throw doubt on the possibility that his 

 fungus could have been a depauperate species of the laterally biflagel- 

 late genus Myzocytium (see p. 973) rather than the present species 

 Olpiclium saccatum, which it resembles, moreover, in all other respects. 



Olpidium utriculiforme Scherffel 



Arch. Protistenk., 54: 213, pi. 10, figs. 84-87. 1926 

 (Fig. 13 B, p. 136) 



Sporangium usually occupying both algal semicells, irregular, tube- 

 like, a simple sac or with a bulging outgrowth or several broad finger- 

 like branches, in large host cells becoming extensive, much branched 

 and consisting of elements up to 550 \x long by 1 1-20 \i wide, wall 

 thick, smooth, colorless, forming a single sessile discharge pore; zo- 

 ospores very numerous, spherical, 2.4-2.8 \x in diameter with a con- 

 spicuous oil globule and a 14-19 \x long fiagellum, movement a smooth 

 gliding or amoeboid; resting spores not observed. 



In desmids, Cosmarium botrytis, Scherffel (loc. cit.), Hungary; 

 Closterium lunula, C. costatum, C. dianeae, Canter (1949b: 25, figs. 

 1 b-3, 3-5, PI. 5), Great Britain; Euastrum bidentatum (Whelden 

 No. 140), Cosmarium conspersum, C. undulatum var. minutum, Cos- 

 marium sp. (F. slide No. 2707), (Whelden Nos. 23, 84), Under ( 1 947 : 242), 

 Canadian Eastern Arctic. 



Olpidium euglenae Dangeard 



Le Botaniste, 4: 248, fig. 10 A-F. 1894-1895 

 (Fig. 13 E, p. 136) 



Sporangium spherical, with a slightly thickened colorless smooth 

 wall, lying eccentrically and loosely in the host cell; zoospores spheri- 



