SPIROGYRA 157 



23. Spirogyra affinis (Hassall) Petit 1880. Les Spirogyres des 



environs de Paris, p. 18, PL 3, Figs. 13-14. 



Vegetative cells 25-30 /x x 35-90 /a, with plane end walls; i chro- 

 matophore, making i to 3.5 turns; conjugation lateral and scalariform; 

 tubes formed by both gametangia; fertile cells globosely inflated; sterile 

 cells not inflated; zygospores ellipsoid, 28-33 /a ^ 30-50 /"■> median spore 

 wall yellow, smooth. 



United States: Michigan; Alaska. 



Widely reported from Europe; Jamaica; China, Kiangsi. 



24. Spirogyra catenaeformis (Hassall) Kiitzing 1849. Species 



Algarum, p. 438. 



Vegetative cells 24-32 /a x 50-135 /a, with plane end walls; i chro- 

 matophore, making i to 6 turns; reproduction by both zygospores and 

 aplanospores; conjugation scalariform and lateral; tubes formed by 

 both gametangia; fertile cells enlarged or inflated, fusiform, sterile cells 

 also inflated; zygospores and aplanospores ellipsoid, 27-33 ju. ^ 55-90 A*-; 

 median spore wall yellow, smooth. (PI. XXII, Fig. 12; PI. XXIV, 

 Fig. 16.) 



United States: Generally distributed throughout. 



Widely distributed in Europe; reported from China, India, and from 

 East and South Africa. 



Distinguished from S. affinis by the longer vegetative cells and the 

 greatly inflated sterile cells; from S. suecica by the symmetrical fusiform 

 inflation of the fertile cells and the ellipsoid spores; from S. subsalina by the 

 yellow spores, generally smaller dimensions, and the less marked inflation 

 of the fertile cells. 



25. Spirogyra subsalina Cedercreutz 1924. Acta Soc. pro Fauna 



et Flora Fennica. 55 (2), p. 4, Fig. 2. 



Vegetative cells 28-38 /x x 70-190 m, with plane end walls; i chro- 

 matophore, making 2 to 4.5 turns; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells inflated to 49-56 /j.; zygospores 

 ellipsoid, 28-38 /a x 42-76 /i-; median spore wall brown, smooth. (PL 

 XXII, Fig. 9.) 



United States: Mississippi, Natchez, April, 1925. 



Finland. 



26. Spirogyra flavescens (Hassall) Kiitzing 1849. Species Al- 



garum, p. 438. 

 Vegetative cells 10-14^1 x 30-50 /x, with plane end walls; i chro- 

 matophore, making i to 3 turns; conjugation scalariform; tubes formed 

 by both gametangia; fertile cells inflated; zygospores ovoid, 20-23 i". x 

 25-40 /a; median spore wall yellow, smooth. (PL XXIII, Fig. i.) 



