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



Var. RUSBYI Wolle, 1887, p. 215, PI. CXXXIX, figs. 7-9. 

 Filaments 62-75 f- diam. ; otherwise like the type. New Mex., 

 N. J.? 



It is not clear from Wolle's account whether he had observed 

 the type in this country, or only the var. Rusbyi, The N. J. 

 reference is in any case doubtful, only sterile plants having been 

 observed. 



9. S. SUBSALSA Kiitzing, 1845, p. 222; Wolle, 1887, p. 212, 

 PI. CXLJ, figs. 3 and 4. Filaments 22-25 /" diam., cells i-i)^ 

 diam. long; chromatophore single, making 1^2-3 turns in the 

 cell ; fertile cells little or not at all swollen ; spore ovoid, slightly 

 longer than the diam.; diam. 18-20 /u,. Florida. Europe. 



Included with some doubt ; the locality is not indicated as 

 brackish. 



10. S. DECIMINA (Miiller) Kiitzing, 1843, p. 279; Petit, 

 1880, p. 25, PI. VIII, figs. 1-3; Wolle, 1887, p. 216, PI. 

 CXXXV, figs. 5 and 6; Wittr. and Nordst., Alg. Exsicc., 

 No. 1372. Filaments 34-40 /u, diam., cells 2-4 diam. long; 

 chromatophores 2, rarely 3, quite broad, making 1-2 turns in 

 the cell ; fertile cells not swollen ; spores broadly ovoid or 

 almost globular, 38X42-75 /A, as broad as the filament. Mass., 

 Pa., Iowa, Jamaica, St. Croix. Europe, Africa. 



Rather common ; usually occurring in large masses, very 

 mucilaginous. 



Var. TRIPLICATA Collins, P. B.-A., No. 960. Chromato- 

 phores uniformly three ; spores 34-48X48-54 p. ; otherwise like 

 the type. Mass., Cal. 



Var. Submarina n. var. Filaments 27-32 /A diam., cells 3-6 

 diam. long; chromatophores 2 or 3, making 1^-3 turns in the 

 cell; spores ellipsoid, 2-3 diam. long, 31-37X56-120 /A ; fertile 

 cells swollen just enough to hold the spore. Mass., Conn. 



Perhaps a good species, but having so many resemblances to 

 S. decimina as to indicate that the differences may be due to the 

 station, salt marsh and brackish pools, an unusual one for a 

 Spirogyra. The principal distinctions are in the slender fila- 

 ments, longer cells, longer spores and somewhat swollen fertile 

 cells. 



ir. S. NITIDA (Dillw.) Link, 1833, p. 262 ; Petit, 1880, p. 

 28, PI. X, figs. 6-10 ; Wolle, 1887, p. 217, PI. CXXXVII, 

 figs. 7 and 8; P. B.-A., No 513. Filaments 72-78 p diam., 

 cells 1^-3 diam. long; chromatophores usually 5, more or less 



