i6o ZYGNEMATACEAE 



Vegetative cells ^8-44/x x 105-160M, with plane end walls; i chro- 

 matophorc; conjugation scalariform; tubes formed by both gametangia; 

 fertile cells cylindric or very slightly swollen; zygospores ovoid, 42-45 m x 

 70-80/1; median spore wall golden-brown, smooth, with suture more 

 or less prominent. (PI. XXIII, Fig. 10.) 



Austria. 



Certainly very close to S. porticalis, perhaps merely a clone; apparently 

 differs in the brown spores with prominent sutures. 



35. Spirogyra porticalis (Miiller) Cleve 1868. F6rs6f{ till en 



monografi. Nova Acta Reg. Soc. Sci. Upsali. Ser. 3, 

 6, p. 22, PI. 5, Figs. 8-9. 



Vegetative cells 40-50 /a x 66-200 m, with plane end walls; i chro- 

 matophore, making 3 to 5 turns; conjugation scalariform; tubes formed 

 by both gametangia; fertile cells cylindric or enlarged; zygospores 

 mostly ovoid to globose-ovoid, 38-50 m x 50-83 /x; median spore wall 

 yellow, smooth. (PI. XXIII, Fig. 9.) 



United States: Very common in the eastern half. 



Widely distributed on all the continents. Found hybridizing with 5. 

 varians at Charleston, Illinois. Hybrid segregates were also present. See 

 Amer. Nat., 53, pp. 109-19, 1919. 



36. Spirogyra sahnii Randhawa 1938. Proc. Indian Acad. Sci. 



^> PP- 339-41- 



Vegetative cells 48-^0 /x x 40-74 /a, with plane end walls; i chro- 

 matophore, making i or 2 turns in the cell; conjugation lateral; tubes 

 formed by both gametangia; fertile and sterile cells inflated; zygospores 

 ovoid, 22-36 /x X 44-68 /x; median wall [?] yellow, smooth; aplanospores 

 similar, 20-24 /x ^ 22-36 /x. 



India, Punjab, Dasuya, March, 1931. 



In the original description the median spore wall is described as 

 "bluish-green." This appearance is probably due to light refraction and 

 colored spore contents. Named for Birbal Sahni of Lucknow University. 



37. Spirogyra lutetiana Petit 1879. Brebissonia. 1, p. 79, PI. 6. 

 Vegetative cells 27-40 /x x 70-250 /x, with plane end walls; i chro- 



matophore, making 3 to 7 turns; conjugation scalariform; tubes formed 

 by both gametangia; fertile cells more or less variable, cylindric, en- 

 larged, or slightly inflated; zygospores polymorphic, varying from glo- 

 bose to ellipsoid and irregular, 25-44^1 x 35-165 m; median spore wall 

 yellow-brown, smooth. (PI. XXIII, Figs. 11-13.) 



United States: Utah; North Dakota; other records very doubtful. 



Widely reported from Europe and Asia; also South Africa. 



Probably none of the species names of Spirogyra has been more frc- 



