378 AQUATIC PHYCOMYCETES 



Sporangium spherical, broadly ellipsoidal, or somewhat pyriform, 

 5-25 [x in diameter, wall thin, smooth, colorless, discharge tube single 

 (rarely two), narrowly cylindrical, straight or contorted, varying in 

 length from a wartlike nearly sessile protuberance 3 \x long to several 

 times the diameter of the sporangium ; rhizoids branched, fairly exten- 

 sive, predominantly arising from a somewhat prolonged basal axis 

 (occasionally two axes), sometimes arising from several places on the 

 lower part of the sporangium; zoospores spherical, 2.5-5 \i in diameter, 

 with a strongly refractive colorless globule and a long fiagellum, emerging 

 singly and somewhat amoeboidly from the orifice of the discharge tube 

 and resting for a time (or clustering temporarily) before swimming 

 away; resting spore formed and borne like the sporangium, spherical, 

 with a thick, faint-golden-brown wall, contents with a large oil globule 

 filling the lumen of the spore, germination not observed. 



In Cladophora glomerata, Cienkowski (he. cit.), Italy (?); dead or 

 moribund Cladophora, Zopf (he. cit.), Minden (1915: 357), Germany; 

 Cladophora glomerata, Sorokin (1883: 34, fig. 41), European Russia, 

 Asiatic Russia; Cladophora sp., Dangeard (1886a: 293), de Wildeman 

 (1894: 158), France; Spirogyra crassa, de Wildeman (1890:7), Bel- 

 gium; Cladophora, Karling (1931a: 443, pi. 35-38), Sparrow (1933c: 

 524), United States; Spirogyra sp., Sparrow (1936a: 452, pi. 14, figs. 

 13-17), parasitic in Oedogonium sp., Spirogyra sp., Richards (1956: 262, 

 pi. 6, fig. 6), Great Britain. 



As understood here, this collective species includes all forms with 

 smooth-walled resting spores and spherical, broadly ellipsoidal, or 

 somewhat pyriform sporangia bearing rhizoids which emerge typically 

 from a main basal axis or less typically from several axes formed on the 

 lower half of the sporangium. Dangeard (/or. cit.) attempted to distin- 

 guish it from Entophlyctis helioformis by the smaller number of rhizoids 

 localized at the base of the sporangium. Such a localization is apparent 

 in most specimens but not in all. This interpretation of the species is 

 at variance with Zopf's statement that the rhizoids arise mostly from 

 all sides of the sporangium. It is possible that it will be better eventually 

 to segregate his species from the present one. Typical of the species as 

 here understood are the figures of Cienkowski (he. cit), Karling (he. cit.), 

 and Sparrow (1936a: pi. 14, figs. 13-17). With this interpretation of 



