978 AQUATIC PHYCOMYCETES 



referable to this form is the fungus reported in Spirogyra from France 

 by Aleem (1952a: 2650). 



Myzocytium megastomum de Wildeman 

 Ann. Soc. Beige Micro. (Mem.), 17: 53, pi. 6, figs. 6-10, pi. 7, figs. 19-20. 1893 

 Ancylistes miurii Skvortzow, Arch. Protistenk., 51: 432, figs. 7-10. 1925. 



Sporangia ovoid, ellipsoidal, spherical, or sometimes pyriform or 

 cylindrical, 9-32 by 12-50 \x (wide?), variable in number, occurring in 

 beadlike linear series, separated by narrow cross walls, discharge tube 

 frequently equatorial, narrowly or irregularly cylindrical, 2.6 u. wide, 

 distinctly expanded (4-6 u.) just beneath the host wall, prolonged 

 extramatrically for a variable distance, up to 150 [x ; zoospores somewhat 

 bean-shaped, 4.5-5 \x long by 5.6-7 \x in diameter, with granular 

 protoplasm bearing several refractive globules and two lateral, opposite- 

 ly directed fiagella of about equal length; gametangia like the sporangia 

 and often occurring with them; oospore spherical, 1 1-15 u. in diameter, 

 with a thick smooth double wall and oily contents, lying loosely in the 

 gametangium, germination not observed. 



In Spirotaenia sp., Closterium sp., C. attenuation, de Wildeman (he. 

 cit.), Belgium; Closterium sp., de Wildeman (1895a: 77), Switzerland; 

 desmid, coll. Massart, de Wildeman (1896b: 47, pi. 3, figs. 22-26), 

 Norway; Closterium acerosum, Scherffel (1914: 17), Hungary; Clos- 

 terium sp., Skvortzow (1925: 431), Manchuria; Cladophora sp., Martin 

 (1927: 188, fig. 1 a-b), Closterium areolatum (?), Berdan (1938:408, 

 fig. 14), Closterium sp., Sparrow and Barr (1955: 556), United States; 

 Cosmarium pericymatium, Rieth (1954: 171, fig. 6), Germany. 



Certain inhabitants of Euastrum referred tentatively by de Wildeman 

 (1895a: 76, pi. 2, figs. 7-9) to Myzocytium proliferum, as well as others 

 called Olpidium immersum by this same investigator (ibid., p. 65, pi. 2, 

 figs. 1-6), all from Switzerland, may be simplified forms of M. megas- 

 tomum. The same might be said of the plant shown in Figure 16d, cited 

 as M. irregulare by Petersen (1909:402, fig. 16d; 1910:538). Rieth 

 (1954: 171) indicates that the zoospores emerge as in Aphano- 

 myces. 



