176 ZYGNEMATACEAE 



spores and 1-2 chromatophorcs. This description obviously disregards all 

 previous descriptions and exsiccatae. 



97. Spirogyra plena (W. & G. S. West) Czurda 1932. Siisswasser- 



flora Mittelewopa. 9, p. 193, Ann. Roy. Bot. Gard., Cal- 

 cutta. 6, p. 187. 1907. 

 Vegetative cells 38-44 m x 57-88 m, with plane end walls; 2 or 3 chro- 

 matophores; conjugation scalariform and lateral; tubes large and 

 formed by both gametangia; fertile cells cylindric or enlarged on the 

 conjugating side; zygospores ovoid, 40-44^1 x 64-73 (-88) /n; median 

 spore wall yellow, smooth. (PI. XXVIII, Figs. 1-2.) 

 United States: Iowa; Indiana; Kentucky; Ohio. 

 Asia, Burma; China, Yunnan; India, Bombay. 



98. Spirogyra szechwanensis Jao 1935. Smensia. 6, p. 595, PI. 6, 



Fig. 69. Amer. ]our. Bot. 23, p. 55. 1936. 



Vegetative cells 75-90 /^ x 125-240 At, with plane end walls; 4 chro- 

 matophorcs, rarely 2 or 3, making 1-2 turns in the cell; conjugation 

 scalariform; tubes formed by both gametangia; fertile cells cylindric; 

 zygospores ellipsoid to ovoid, 57-68 m x 100-210 m; median spore wall 

 smooth, yellow at maturity. (PI, XXVIII, Fig. 3.) 



China, Chungking. 



99. Spirogyra jugalis (F1. Dan.) Kiitzing 1845. Phycologia Ger- 



manica, p. 223. 



Vegetative cells 75-103 m x 80-300 /x, with plane end walls; 3 to 4 

 chromatophorcs, making i to 2 turns; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells cylindric or enlarged; zygo- 

 spores ovoid, 87-108 /i. x 120-155 /x; median spore wall brown, smooth. 

 (PI. XXVIII, Fig. 4.) 



United States: Minnesota; Iowa; Illinois; Michigan; Massachusetts. 



Europe; China. 



100. Spirogyra margaritata Wollny 1877. Hedivigia. 16, p. 164. 

 Vegetative cells ioo-120/x x i50-400iu, with plane end walls; 13 to 



15 chromatophorcs, making .25 to .5 turns; conjugation scalariform; 

 tubes formed by both gametangia; fertile cells cylindric or inflated to 

 165)".; zygospores ovoid, 92-125/^ x 140-200/1; median spore wall smooth, 

 brown. (PI. XXVIII, Fig. 5.) 



Germany, Dresden. 



Thirty years ago Dr. Nordstedt sent me dried material of this species 

 collected by R. Wollny in 1877, which I assume to be a part of the type 

 collection. Most of the spores are immature, but are globose only when seen 

 along the long axis. The above details are based on this collection and 

 complete the description. 



