n6 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



turns iu the cell ; fertile cells much swollen, vesicular, not 

 shortened, extreme diam. 37-42 p. ; spores ellipsoid, yellow at 

 maturity, 2 diam. long, diam. about 30 /A. Mass., R. I. 



Eiirope, New Zealand. 



The smallest of our species and easily recognized. 



29. S. INFLATA (Vauch.) Kiitzing, 1843, p. 279; Petit, 1880, 

 p. 7, PL I, figs. 4-6 ; Wolle, 1887, p. 207, PI. CXXXII, figs. 6 

 and 7; P. B.-A., No. 363. Filaments 15-18 /A diam., cells 3-8 

 diam. long ; chromatophore single, quite broad, making 3-8 

 turns in the cell ; fertile cells much swollen, somewhat shortened, 

 42-48 i*. diam.; spores ellipsoid, dark yellow at maturity, 2 diam. 

 long, diam. 30-36 p. Mass., Conn., N. J. Europe. 



Resembles .5". temtissima, but larger, with broader and more 

 densely twisted spiral. 



30. S. SPREEIANA Rabenhorst, Algen, No. 988; Petit, 1880, 

 p. 7, PI. I, figs. 7-9 ; Wolle, 1887, p. 208, PI. CXXXII, figs. 4 

 and 5; P. B.-A., No. 1019. Filaments 18-21 /u, diam., cells 

 10-25 diam. long; chromatophore single, slender, making 1^-4 

 turns in the cell ; fertile cells swollen, not shortened, 30-42 /A 

 diam.; spores ellipsoid, yellowish at maturity, 2-3 diam. long, 

 diam. up to 36 p. Mass., Washington, Cal. Europe. 



The very long cells, with a loose, almost inconspicuous spiral, 

 the swelling in the fertile cells tapering to each end of the cell r 

 sufficiently distinguish this species. 



31. S. OUADRATA (Hass.) Petit, 1874, p. 41, PI. I, fig. 2; 

 1880, p. 8, PL I, fig. 13; Wolle, 1887, p. 208, PL CXXXII, 

 figs. S-io; P. B.-A., No. 366. 5". bifaria (Bailey) Kiitzing, 

 i855a, p. 7, PL XXI, fig. 3. Filaments 24-27 /u, diam., cells 3-9 

 diam. long; chromatophore single, broad, making 1^2-5 turns 

 in the cell ; fertile cell much swollen, up to 54 ^ diam., appear- 

 ing like a rectangle with rounded corners ; spores ellipsoid or 

 cylindric-ellipsoid, brown at maturity, 1^2-2 diam. long, diam. 

 42-48 /j.. Mass., N. Y., Pa. Europe. 



Easily recognizable by the peculiar shape of the fertile cells. 

 According to Wolle, S. pulchella Wood, 1872, p. 164, PI. XIV, 

 fig. 2, is a synonym of this species. The plate, though appar- 

 ently not very characteristic, does not contradict this conclu- 

 sion. Zygnema bifaria Bailey, from examination of authentic 

 specimens, agrees fully with .5". quadrata. 



32. S. WEBERI Kiitziug, 1843, p. 279 ; Petit, 1880, p. 9, PL I, 

 figs. 10-12; Wolle, 1887, p. 208, PL CXXXII, fig. u ; P. B.-A., 

 No. 368. Filaments 22-28 /A diam., cells 6-16 diam. long; 



