732 AQUATIC PHYCOMYCETES 



Monoblepharis polymorpha var. macrandra Lagerheim, Bih. Kgl. Svensk. 

 Vetensk.-Ak. Handl., 25, Afd. 3, No. 8: 35, pi. 1, figs. 2, 4, 21-24, 36-46, 

 48-51, 54, 63, 67-68, pi. 2, figs. 1 1-26. 1900. 



Mycelium filamentous, exceedingly well developed, consisting of 

 rather flexuous nearly isodiametric profusely branched hyphae which un- 

 der excellent conditions for growth may interlock and completely envel- 

 op the substratum, hyphae 5 [i tapering distally to 1.5-2 u. in diameter, 

 bearing occasional irregular swellings; sporangia narrowly cylindrical, 

 107-346 jx in length by 4.5-6 ^l in diameter, occurring singly at the tips 

 of the hyphae or grouped in sympodial or fasciculate fashion, occasion- 

 ally proliferating ; zoospores 7.8 \x in diameter by 9-12 jx in length; 

 oogonia broadly cylindrical to narrowly pyriform, at first formed singly 

 in a terminal or intercalary position, later occurring sympodially or 

 more commonly in fascicles associated with antheridia ; antheridia cy- 

 lindrical, at first formed at the tips of hyphal branches other than those 

 bearing oogonia, later occurring with them, always strongly exserted, 

 variable in size, usually about 12.5-59 \i long by 5-7 u. in diameter; 

 antherozoids from five to fourteen in an antheridium, about 6 u. in 

 length by 4 \x in diameter; oospores normally exogenous, having a 

 tendency to fall away from the oogonium, 13-25 [i. in diameter, the 

 brown wall covered by lighter-colored bullations 1.5-2 \x in height, 

 germination not observed. 



Saprophytic on submerged twigs of various types. Lagerheim (loc. 

 cit.), Sweden; Woronin (loc. cit.), Finland; Cornu (loc. cit), France; 

 Tiesenhausen (1912:266), Switzerland; Petersen (1909:399; 1910: 

 535, fig. 15c), Lund (1934: 45), Denmark; Minden (1915: 476), Laibach 

 (1926: figs. 1-3; 1927: figs. 5, 7b, 9-10, pi. 12, figs. 1-19, 28-35, pi. 13, 

 figs. 36-47), Hohnk (1935: 219), Germany; Wettstein (1921), Austria; 

 Thaxter (F.), Sparrow (S.) (1933b: 530, fig. 1 s-u, pi. 20, figs. 5-6, 25, 

 31 ; 1933c: 530), twigs, Beneke (1948: 30), Sparrow (1952d: 769), R. M. 

 Johns (comm.), (North Carolina), United States; Scherffel (1931: 

 137), Hungary; Barnes and Melville (1932: 86, figs. 2-5), Sparrow 

 (1933b: 530; 1936a: 459), twigs of Quercus robur, Fraxinus excelsior, 

 Ulmus sp., Perrott (1955: 275, pi. 13, figs. 1-2, 14-15), Great Britain. 



If one combines the description of variations found in Monoblepharis 

 polymorpha given at the top of page 84 of Cornu's monograph with the 



