i88 ZYGNEMATACEAE 



146. Spirogyra cylindrospora W. & G. S. West 1897. Jour. Bot. 



35, p. 42. 



Vegetative cells 70-77 /x x 100-300 /n, with plane end walls; 4 chro- 

 matophores, making i to 3 turns; conjugation scalariform and lateral; 

 tubes formed by both gametangia; fertile cells cylindric; zygospores 

 cylindric-ovoid, 70-77/1 x 78-98 /x; median spore wall yellow, punctate- 

 scrobiculate, thick. 



Central Africa. 



147. Spirog\tia echinospora Blum 1943. Amer. Jour. Bot. 30, 



p. 783, Figs. 1-2. 



Vegetative cells 66-72 /n x 50-125/^, with plane end walls; 6-7(-8) 

 chromatophores, making .5 to 1.5 turns in the cell; conjugation scalar- 

 iform; tubes wide and formed by both gametangia; fertile cells more 

 or less inflated on the conjugating side; zygospores ovoid, 67-82 m x 

 98-150/x; median spore wall thick, brown-black, cchinate. (PI. XXX, 

 Figs. 17-18.) 



United States: New Hampshire. 



148. Spirogyra diluta Wood 1869. Proc. Amer. Phil. Soc. (1869), 



p. 139. Phycoth. Bor.-Amer., No. 513. 



Vegetative cells 70-85/1 x 80-160/1., with plane end walls; 5 to 8 

 chromatophores, straight or making i turn; conjugation scalariform; 

 tubes formed by both gametangia; fertile cells enlarged or inflated on 

 the inner side; zygospores ovoid, 66-90/1 x 90-130/1; median spore wall 

 chestnut brown, verrucose-reticulate to verrucose. (Pi. XXX, Figs. 

 19-20.) 



United States: Illinois to Massachusetts and Connecticut. 



In Figure 19 note short gametangia with spores oriented at right angles 

 to the filaments. Similar gametangia occur in species Numbers 141, 147, 



149. 150, 151, also in Numbers 171, 176, and 177. 



149. Spirogyra echinata Tiffany 1924. Ohio Jour. Sci. 24, p. 180, 

 PI. I, Fig. I. 



Vegetative cells 88-96/t x 84-106/1, with plane end walls; 4 to 7 

 chromatophores, making .5 to 1.5 turns; conjugation scalariform; tubes 

 formed by both gametangia; fertile cells shortened and inflated on the 

 conjugating side; zygospores ovoid, 68-85/1 x 76-120/1, often placed 

 transversely to the filament; median spore wall reticulaie-echinate, 

 brown. (PI. XXXI, Figs. 1-2.) 



United States: Iowa, Montgomery. 



South Africa (Stephens Coll.). 



