LAGENIDIALES 999 



(1904:117), Hungary; Spirogyra varians, S. insignis, S. calospora, 



Atkinson (1909a), zygospores of Spirogyra sp., Wolf (1944: 15), United 

 States; Spirogyra maxima, Voronichin (1920: 12), Russia; zygote of 

 Spirogyra sp., Shen and Siang (1948 : 202, fig. 1 3), China; Spirogyra sp., 

 Lacy (1949: 134, fig. 1, A), India; zygospores of Spirogyra sp., Sparrow 

 (1952c: 105), Cuba. 



Lagenidium americanum Atk. is said to differ in the lack of a swelling 

 on the discharge tube, but the figures do not seem to bear out this 

 statement. From Zopf 's description and figures this swelling is apparent- 

 ly not a constant feature. 



The fungus described by Cook (1935: 77, pi. 2, figs. 15-25, pi. 3, figs. 

 33-35) from Great Britain, though occasionally branched, does not 

 possess the distinctly tubular, contorted, and lobulate appearance 

 characteristic of Zopf 's fungus. The sporangia are 12-15 [x long by 4-6 \l 

 in diameter, the zoospores 8 a long by 4 ;jl in diameter, and the parthe- 

 nogenetically developed oospores spherical and 1 2 [jl in diameter. Further 

 study may show this to be a new species. 



Fischer (1892: 82) states that Carter (1856) confused this fungus with 

 the developmental stage of an Astasia-like flagellate. 



All of the abundant material observed by Sparrow (1952c) formed 

 oospores bearing a network of low dentations on the outer wall, as was 

 figured by Zopf. This, we believe, to be typical for the species. The Cuban 

 fungus caused a devastating epidemic in zygospores of the host. 



Lagenidium gracile Zopf 



Nova Acta Acad. Leop.-Carol., 47:158. 1884 



Thallus tubular, somewhat irregular, coiled, branched, slender, 4.5 [J. 

 in diameter, forming a series of cylindrical or spherical sporangia, each 

 provided with a very narrowly cylindrical discharge tube which is 

 expanded beneath the wall of the host gametangium (but not the zygo- 

 spore) and extends for a short distance extramatrically ; zoospores bean- 

 shaped, 7.5 [x long by 4 [x wide, with two equal flagella, formed in a 

 vesicle (?) at the tip of the discharge tube; female gametangium inter- 

 calary; rarely terminal, spherical or nearly so; resting spore parthe- 

 nogenetically formed, lying loosely in the gametangium, spherical, 13- 



