158 ZYGNEMATACEAE 



United States: Michigan; Massachusetts; Florida. 

 Widely distributed in Europe; reported from Australia. 



27. Spirogyra subsalsa Ki'itzing 1845. P/iycologia Germanica, 



p. 222. 



Vegetative cells 22-26 /n x 35-100/1, with plane end walls; i chro- 

 matophorc, making 2 to 5 turns; conjugation scalariform; tubes formed 

 largely by the male gametangia, fertile cells inflated; zygospores ovoid, 

 18-27/t X 30-52/1; median spore wall yellow-brown, smooth. (PI. XXIII, 

 Fig. 2.) 



United States: Wisconsin (Prescott Coll.); Florida. 



Sweden; Holland; France; Czechoslovakia; Java. 



28. Spirogyra paludosa Czurda 1932. Siisswasserflora Mittel- 



europa. 9, p. 167, Fig. 170. 



Vegetative cells 18-20/j. x 55-78 /t, with plane end walls; i chro- 



matophore; conjugation scalariform; tubes formed by both gametangia; 



fertile cells somewhat swollen; sterile cells cylindric; zygospores ovoid, 



24M X 46-48M; median spore wall golden-brown, smooth. (PI. XXIII, 



Fig- 3-) 



Czechoslovakia. 



29. Spirogyra mirabilis (Hassall) Kiitzing 1849. Species Al- 



garum, p. 438. 



Vegetative cells 23-29 yu. x 70-200 m, with plane end walls; i chro- 

 matophore, making 4 to 7 turns; reproduction by aplanospores, very 

 rarely by scalariform conjugation; tubes formed by both gametangia; 

 sporangia enlarged or inflated; aplanospores and zygospores ovoid, less 

 frequently varying to ellipsoid, 23-29/1. x 50-83/1; median spore wall 

 yellowish-brown, smooth. (PI. XXIII, Fig. 4.) 



United States: From Colorado, Wisconsin, and Texas, to Maine and 

 North Carolina. 



Widely distributed in Europe; recorded from Siberia, Manchuria, 

 China, and Afghanistan. See also S. aplanospora (No. 38), and S. maravil- 

 losa (No. 65). Only a few zygospores have been seen among the hundreds 

 of aplanosporic filaments studied. 



30. Spirogyra i.ongata (Vaucher) Kiitzing 1843. Phycologia 



Generalis, p. 279. Vaucher. Histoire des Conserves, PL 6. 



1803. Includes S. circumscissa Czurda 1932, not S. longata 



(Vaucher) Czurda. 

 Vegetative cells 26-38/1 x 45-280/1, with plane end walls; i chro- 

 matophore, making 2 to 5 turns; conjugation scalariform and lateral; 

 tubes formed by both gametangia; zygospores ovoid, varying in some 



