SPIROGYRA 179 



formed by both gametangia; fertile cells inflated, oblong; zygospores 

 ovoid, or oblong-ovoid, 41-43 /^ x 52-71 /i.; median wall densely scrobic- 

 ulate. (PI. XXVIII, Fig. 10.) 



United States: Wisconsin (Prescott Coll.). 



Central Africa. 



1 10. Spirogyra rhizopus Jao 1936. Amer. Jour. Bot. 23, p. 55, 



Figs. 10-12. 



Vegetative cells 25-32 /a x 80-250 m, with plane end walls; 2 chro- 

 matophores, making 1.5 to 4 turns; basal cell with much expanded and 

 irregularly lobed holdfast; conjugation scalariform; tubes formed by 

 both gametangia; fertile cells quadrangularly inflated, sometimes oblong 

 in form, to 57^".; zygospores ellipsoid, 35-42;^. x 64-ioo/x; outer spore 

 wall thick, lamellose, colorless; median spore wall brown, irregularly 

 reticulate. (PI. XXVIII, Figs. 11-13.) 



China, Peiping, July, 1927. 



111. Spirogyra dictyospora Jao 1935. Sinensia. 6, p. 599, PL 8, 



Fig. 84. 



Vegetative cells 28-32 /ax 55-144M, with plane end walls; chroma- 

 tophores 3, sometimes 2, making 2-5 turns in the cell; conjugation 

 scalariform; tubes formed by both gametangia; fertile cells enlarged up 

 to 55 /a; zygospores ovoid, 41-55 /x x 61-103 ft; median spore wall retic- 

 ulate, yellow to yellow-brown. (PI. XXVIII, Fig. 14.) 



China, Chungking, February, 1930. 



112. Spirogyra natchita Transeau 1934. Trans. Amer. Micros. 



Soc. 53, p. 225. 



Vegetative cells 32-36^1 x 120-200 ju, with plane end walls; i to 3 

 (mostly 2) chromatophores; conjugation scalariform; tubes formed by 

 both gametangia; fertile cells inflated to 62 /a; zygospores ovoid, <^6-6o{x 

 x 90-114^1.; median spore wall yellow-brown, punctate and reticulate. 



United States: Texas and Mississippi. 



113. Spirogyra fossa Jao 1935. Trans. Amer. Micros. Soc. 54, 



p. 3, PI. I, Fig. 6. 



Vegetative cells 19-22 /a x 96-192 /a, with plane end walls; 2 chro- 

 matophores, making i to 5 turns; conjugation scalariform; tubes formed 

 by both gametangia; fertile cells enlarged to 33/1.; zygospores ellipsoid, 

 27-32 /A X 48-77 /a; median spore wall yellow-brown at maturity, with 

 irregular, tortuous grooves, or corrugations. (PI. XXVIII, Figs. 15-16.) 



United States: Massachusetts, Pasque Island, June 26, 1924. 



