278 AQUATIC PHYCOMYCETES 



In both cases the chytrid was found on worms harboring other 

 fungi. In the American material it occurred with Harposporiwn anguil- 

 lulae, and in the British with undetermined species of Lagenidium and 

 Aphanomyces. 



The fungus has previously been discussed as Rhizophydium sphaero- 

 carpum (Zopf) Fischer, but it differs from that species in certain minor 

 features (see p. 274). Buckley and Clapham (1929: 6, text figs. 19-21, 

 pi. 1, figs. 1-3) have described as R. carpophilum a fungus on eggs of 

 Dibothriocephalus latus (a helminth), in England, which may possibly 

 be referable to the present species. The sporangia were larger (up 

 to 35 [x in diameter), and the main rhizoid formed delicate branches 

 at its tip. The zoospores, however, were the same size (4.5-5 jx) as 

 those of R. vermicola. 



Rhizophydium mischococci Scherffel 



Arch. Protistenk., 54: 195, pi. 9, fig. 56. 1926 



(Fig. 17 R, p. 228) 



Sporangium sessile, broadly pyriform, with a thin smooth color- 

 less wall, 5 [x high by 5 [x in diameter (at the base); endobiotic system 

 consisting of a long, fairly thick, unbranched rhizoid; zoospores four, 

 each with a fairly large colorless globule, escaping through an apical 

 pore, the wall of the sporangium collapsing after discharge, motile 

 zoospores not seen; resting spore not observed. 



On Mischoeoccus confervicola, Hungary. 



Scherffel asserted that if Phlyctidium is segregated from Rhizophy- 

 dium — which he does not favor — his fungus more properly belongs 

 in the former genus. It is retained here because its slender rhizoid 

 is uninflated and not haustorial, as in typical Phlyctidium. 



Rhizophydium agile (Zopf) Fischer 



Rabenhorst. Kryptogamen-Fl., 1 (4): 96. 1892 



Rhizophyton agile Zopf, Nova Acta Acad. Leop.-Carol., 52:343, pi. 20, 

 figs. 1-7. 1888. 



Sporangia occurring singly or in groups on the surface of the gelat- 

 inous sheath of the host, sessile, variable in shape, broadly pyri- 



