192 ZYGNEMATACEAE 



chromatophores, making .i to i turn; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells shortened and inflated; zygo- 

 spores lenticular, 60-90M x 48-60/1; median spore wall brown, irreg- 

 ularly pitted. (PI. XXXI, Figs. 17-1S.) 



United States: Missouri to Massachusetts and Florida. 



Europe; Australia; South Africa. 



162. Spirogyra moebii Transeau 1934. Trans. Amer. Micros. Soc. 



53, p. 225. S. maxima var. minor Mocbius. Flora. 75, 

 p. 421. 1892. 

 Vegetative cells So-iiy ix x 130-240 /.i, with plane end walls; 6 to 8 

 chromatophores, making .5 to i turn; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells cylindric; zygospores lentic- 

 ular, 74-100 /x X 56-65 ju; median spore wall yellow-brown, reticulate. 

 United States: Oklahoma (Taft Coll.). 

 Europe; Australia, Queensland. 



163. Spirogyra oblata Jao 1936. Amer. Jour. Bot. 23, p. 58, 



Figs. 29-31. 



Vegetative cells 96-11 8 m x 80-256/', with plane end walls; 9 to 13 

 chromatophores, nearly straight, or making up to .6 turn; conjugation 

 scalariform; tubes formed by both gametangia; fertile cells shortened, 

 cylindric; zygospores lenticular, 93-106A1 x 64-70/<.; outer wall thick, 

 smooth, and lamellate; median spore wall yellow-brown, verrucose. 

 (PI. XXXII, Figs. 1-3.) 



China, Hangchow, June, 1929. 



164. Spirogyra Formosa (Transeau) Czurda 1932. Siisswasser- 



flora Mitteleuropa. 9, p. 203. S. crassa var. formosa. Ohio 

 Jour. Sci. 16, p. 27. 1915. 



Vegetative cells 80-95/1. x 80-270/1, with plane end walls; 6-12 

 chromatophores, making .5 to i turn in the cell; conjugation scalar- 

 iform; tubes formed by both gametangia; fertile cells cylindric; zygo- 

 spores compressed-ovoid, 88-100/1 x 120-150/1 x 70-90/1; median spore 

 wall brown, with irregular, shallow pits. (PI. XXXII, Fig. 4.) 



United States: Illinois, Ashmore, June 18, 191 3. 



Spores arc broadly ovoid in one plane and narrowly ovoid when viewed 

 at right angles. 



165. Spirogyra jassiensis (Teodoresco) Czurda 1932. Siisswasser- 



fiora Mitteleuropa. 9, p. 203. Beih. Bot. Zentralbl. 21, 

 p. 189. 1907. 

 Vegetative cells 116-1:52 /i x 116-250 /i, with plane end walls; 8 to 9 

 chromatophores, making .5 to i turn; conjugation lateral; tubes formed 



