380 AQUATIC PHYCOMYCETES 



This is the most ubiquitous member of the genus. It is abundant in 

 dead plants of Chara and Nitella. Karling, who studied the development 

 of what is probably not this species (loc. cit.), later reported (1931a: 443) 

 negative results in his attempts to grow the fungus on moribund and 

 dead sterile internodes of Chara and Nitella, or on filaments of Spiro- 

 gyra, Vaucheria, Oedogonium, Mougeotia, and Hydrodictyon. 



Although the rhizoids are said by some investigators to be extensive 

 and profusely branched, in the present writer's material they were for 

 the most part as Dangeard figured them, that is, relatively short and 

 once-branched. The diagnosis, therefore, is in conformity with Dang- 

 eard's original description. 



The change in specific name from the Greek-Latin hybrid helioformis 

 to heliomorphum was made by Dangeard without explanation. 



Entophlyctis aurea Haskins 



Trans. Brit. Mycol. Soc, 29: 138, figs. 9-15; pi. 8. 1946 



"Zoosporangia usually intramatrical, spherical or variously shaped, 

 15-470 \x in diameter; contents yellow to pale orange in colour when 

 young, bright orange at maturity; wall hyaline and layered, innermost 

 layer giving marked cellulose reaction with chloriodide of zinc, outer 

 layer not staining. Exit tubes one to ten, short with reflexed rims, 4.2-21 

 [i in diameter at orifice, 5.3-35.7 [i at base, 6.3-50.3 u. in height, with 

 gelatinous plugs. Rhizoids arising from one to twenty places on the 

 sporangium, stout, up to 63 u. in diameter at point of origin, cut off 

 from mature sporangium by cellulose cross-walls; much branched, 

 extending up to 750 \x in length. Zoospores spherical to subspherical, 

 4.5-5.2 [j. in diameter, with several small refractive granules or glob- 

 ules; uniflagellate, flagellum five times diameter of zoospore in length: 

 number of zoospores great, emerging initially through one exit tube 

 to form a spherical or irregular mass, lying quiescent for a few moments 

 before swimming away, remaining zoospores escaping through all exit 

 tubes; movement gliding and darting, intermittently amoeboid. Resting 

 spores borne and shaped similarly to zoosporangia, 22-106 \i in diame- 

 ter, contents with one to several large orange-brown globules (1 1.4-60.8 

 (jl in diameter), with or without smaller parietal colourless globules; 



