Spirogyra nitida (Dillw.) Link 1833, p. 262 

 PL 73, Fig. 10 

 Filaments of rather stout cells, 60-80/* in diameter, 90-166- ( 170 )iU, 

 long, with plane end walls; chloroplasts 3-5, making i/o to l^/o turns. 

 Conjugation by tubes from both gametangia; fertile cells cylindric. 

 Zygospores ellipsoid or cylindiic-ellipsoid, with sharply rounded 

 poles; median spore wall smooth and brown; 60-77-(85)/x in diam- 

 eter, 90-1 18- ( 170) /x long. 



Tychoplankter; in shallow water of lakes and marshes. Mich., Wis. 



Spirogyra novae-angliae Transeau 1915, p. 26 

 PI. 75, Figs. 1-3 

 Filaments of rather stout cells, 49-60/x in diameter, 140-240-(390)/x 

 long, with plane end walls; chloroplasts 3-5, broad, making li/o to 4 

 turns. Conjugation by tubes from both gametangia; fertile cells 

 cylindric. Zygospores ovate to ovate-ellipsoid; median spore wall 

 irregularly reticulate and brown; 50-60)u. in diameter, 82-92- ( 120 )/i, 

 long. 



Forming sparse floating clots in several lakes. Mich., Wis. 



Spirogyra orientalis West & West 1907, p. 186 



Vegetative cells 30-31/* in diameter, 90-160/x long, with plane end 

 walls; chloroplasts 3, making 1 to I1/2 turns. Conjugation scalariform 

 by tubes from both gametangia; fertile cells inflated. Zygospores 

 ellipsoid; median spore wall finely scrobiculate; 32-42/* in diameter, 

 61-67/* long. 



Mich. 



Spirogyra porangabae Transeau 1938, p. 525 

 PL 77, Figs. 2, 3 



Vegetative cells 11-14.5/* in diameter, 65-145/* long, with plane 

 end walls; chloroplast sohtary, making 4 to 9 turns. Conjugation 

 scalariform by tubes from both gametangia; fertile cells slightly 

 inflated (or merely enlarged to contain the spore). Zygospores 

 ellipsoid; median spore wall irregularly punctate when mature, 

 yellow; 21-27/* in diameter, 47-54/* long. 



Mich. 



Spirogyra porticalis ( Muell. ) Cleve 1868, p. 22 



PL 75, Fig. 10 



Filaments of rather stout cells, 40-50/* in diameter, 68-200/* long, 



with plane end walls; chloroplast solitary, making 3 to 4 turns. 



Conjugation scalariform by tubes from both gametangia; fertile 



[318] 



