214 ZYGNEMATACEAE 



2 chromatophores, making 3 to 9 turns; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells inflated up to 67 /x; zygospores 

 ovoid to ovoid-globose, 40-57 /^ x 60-10^/1; outer spore wall of 2 layers, 

 of which the inner is hyaline, scrobiculate; median spore wall yellow- 

 brown, smooth. (PI. XXXVIII, Fig. 2.) 



United States: Illinois; Ohio; Maine. 



Latvia; Germany. 



241. Spirogyra tolosana Comere 1899. Bull. soc. hot. de ¥ ranee. 



46, p. 168, PL 3, Figs. 1-3. 



Vegetative cells 28-30 ju. x 225-300 /a, with replicate end walls; 2 

 chromatophores, making 3.5 to 4 turns; conjugation lateral; fertile cells 

 cylindric or enlarged and shortened; zygospores cylindric-ovoid, with 

 ends more or less truncate when filling the gametangium, 26-29 m x 

 95-108 m; median wall yellow-brown, smooth. (PI. XXXVIII, Fig. 3.) 



United States: Indiana, Clay and Vigo Counties (Ben Smith Coll.). 



France, Toulouse. 



Approaches S. hassallii, differs in having smaller ovoid spores. 



242. Spirogyra hassallii (Jenner) Petit 1880. Les Spirogyres 



des environs de Paris, p. 13, PL 2, Figs. 6-8. 



Vegetative cells 26-33 ft ^ 100-250 /x, with replicate end walls; 2 

 chromatophores, making 1.5 to 5 turns; conjugation lateral and scalar- 

 iform; fertile cells fusiform, inflated to 50^1; tubes formed by both 

 gametangia; zygospores ellipsoid, 39-48 )«. x 58-136 jn; median spore wall 

 yellow, smooth. (PL XXXVIII, Fig. 4.) 



United States: Colorado; North Dakota; Iowa; Illinois; to the New 

 England states. 



Widely distributed in Europe and eastern Asia. 



243. Spirogyra hartigii Kiitzing 1855. Tabulae phycologicae. 5, 



P- 33- 



Vegetative cells about 45 /x x 500-675/'., with replicate end walls; 2 

 chromatophores, making 2 turns; conjugation lateral and scalariform; 

 tubes formed by both gametangia, longer than usual; and in lateral 

 conjugation the tube primordia arise 4 to 5/u. from the end walls; recep- 

 tive gametangia enlarged or slightly inflated at the middle; zygospores 

 ovoid, 45-50 jti x 80-105 /x; median spore wall smooth. (PI. XXXVIII, 

 Figs. 5-<).) 



Germany. 



The dimensions of the spores are inferred from the figures published. 

 The other characteristics are so striking that although the description is not 

 complete the alga can be identified when collected. See also Number 245, 

 S. ftroavita Langer, and Number 264, S. crassispina lao. 



