SPIROGYRA 215 



244. Spirogyra gratiana Transeau 1938, Amer. Jour. BoL 25, 



p. 528, Figs. 12-13. 



Vegetative cells 28-33 /x x 144-400 /a, with replicate end walls; usually 

 3 chromatophores (rarely in some cells 2 or 4) ; conjugation lateral and 

 scalariform ; tubes formed by both gametangia; receptive gametangia 

 cylindric or enlarged; zygospores ellipsoid, 35-47 Ai x 108-223 ju.; all walls 

 smooth; median wall yellow; aplanospores infrequent, smaller, 38-40^0. 

 X47-72A^. (PL XXXVIII, Figs. 8-^.) 



United States: Minnesota, Grand Marais, June 17, 10^6 (Grace Nichols 

 Coll.). 



The filaments are remarkable in that they are almost perfecdy straight 

 during and after conjugation. 



245. Spirogyra proavita Langer 1913. Boi. KdzlemenyeJ^. 12, 



p. 166. 



Vegetative cells 37-40 jU, x 330-560 fi, with replicate end walls; 2-3 

 chromatophores, making i to 3.5 turns in the cell; conjugation lateral; 

 tubes arising from primordia several microns away from the end wall, 

 thus forming a distinct tube outside the filament; fertile cells cylindric; 

 zygospores ovoid, 38-40 /x x 82-86 ju.; median spore wall smooth, brown- 

 ish-yellow when mature. (PI. XXXVIII, Fig. 7.) 



Hungary. 



This species resembles Number 243, S. hartigii, in important partic- 

 ulars and perhaps is a somewhat smaller variant; differs from Number 264, 

 S. crassispina, in having ovoid spores. 



246. Spirogyra transeauiana Jao 1935. Sinensia. 6, p. 610, PI. 10, 



Fig. 107. 



Vegetative cells 42-61 /i. x 160-304;^, with repHcate end walls; 2 to 3 

 chromatophores, making 2 to 5 turns; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells cylindric or slightly enlarged 

 on the conjugating side; zygospores ellipsoid with rounded ends, 

 41-58 /x x 96-183/U.; median spore wall yellow, smooth. (PI. XXXVIII, 

 Fig. 10.) 



China, Szechwan. 



247. Spirogyra rectangularis Transeau 1914. Amer. Jour. BoL 



1, p. 291, PI. 25, Figs. 9-11. 



Vegetative cells 35-40 /i x 1 50-320 /x, with repHcate end walls; 2 to 4 

 chromatophores, making 2 to 5 turns; conjugation lateral and scalar- 

 iform; tubes formed by both gametangia; fertile cells cylindrically in- 

 flated to 48-70^; zygospores ovoid to cylindric-ovoid, 45-65 /x x 75-120 /j.; 

 median spore wall yellow-brown, smooth. (PI. XXXVIII, Figs. 11-12.) 



