1 62 ZYGNEMATACEAE 



41. Spirogyra occidentalis (Transeau) Czurda 1932. Siisswasser- 



flora Mitteleuropa. 9, p. 183. 



Vegetative cells 40-50^ x 125-300/^, with plane end walls; chro- 

 matophores i, 2, or 3, making 2 to 6 turns in the cell; conjugation 

 scalariform; tubes formed by both gametangia; fertile gametangia 

 cylindric or inflated to 66/^; zygospores ovoid to cylindric-ovoid, 

 36-56/n X 57-105/^; median spore wall smooth, yellow-brown; outer 

 wall of 2 layers, of which the inner is hyaline, scrobiculate. (PI. XXIV, 

 Fig. 2.) 



United States: Iowa; Illinois; Indiana; Ohio; Kentucky. 



Canada, British Columbia (Phycoth. Bor.-Amer., No. 961). 



Resembles S. velata but has larger dimensions throughout. 



42. Spirogyra luteospora Czurda 1932. Susswasserflora Mittel- 



europa. 9, p. 181. 



Vegetative cells 22-24 /i ^ 55~90'^» w'wh plane end walls; i chro- 

 matophore; conjugation scalariform; tubes formed by both gametangia; 

 fertile cells cylindric or enlarged by the spores; zygospores ovoid to 

 cylindric-ovoid, 25-26^1 x 38-46/Li; median spore wall golden-brown, 

 scrobiculate; pits about 2/^ in diameter. (PI. XXIV, Fig. 3.) 



Bohemia. 



43. Spirogyra sulcata Blum 1943. Amer. Jour. Bot. 30, p. 783, 



Figs. 9-11. 



Vegetative cells ^7-46 m x 50-160 ju,, with plane end walls; i(-2) 

 chromatophores, with prominent median furrow, making 2 to 5 turns 

 in the cells; conjugation scalariform; tubes formed by both gametangia; 

 fertile cells inflated on the outer side; zygospores ovoid, 43-46111 x 52- 

 62 fj.; median spore wall thick, brown, and reticulate. (PI. XXIV, Fig. 4.) 



United States: Wisconsin, Madison. 



44. Spirogyra westii Transeau 1934. Trans. Amer. Micros. Soc. 



53, p. 224. S. porticalis var. ajricana G. S. West 1907. 



]our. Linn. Soc. of London Bot. 38, p. 105. 



Vegetative cells 40-41 /i x 60-160/'., with plane end walls; i chro- 



matophore, making 3 to 5 turns in the cell; conjugation scalariform; 



tubes formed by both gametangia; fertile cells enlarged; zygospores 



ovoid, about 58 /x x 93 /a; median spore wall finely wrinkled, or corrugate. 



Africa, Tanganyika. 



45. Spirogyra obovata Jao 1935. Sinensia. 6, p. 596, PI. 7, Fig. 73. 

 Vegetative cells 25-29/A x 70-182/1, with plane end walls; i chro- 



matophore (rarely 2), making 2.5-6 turns in the cell; conjugation 



