30 TUFTS COLLEGE STUDIES, VOL. IV, No. 7 



p. 158, fig. ii. Cells arcuate, acuminate, 30-80^1 long, 5-7 M 

 wide, chrotnatophore notched at the middle, with two pyrenoids. 

 Wis., G. M. Smith. Europe. 



The description belongs to the European plant ; the Amer- 

 ican plant, while agreeing as to dimensions, notched chromato- 

 phore and pyrenoids, is usually straight or slightly curved. 



CLOSTERIOPSIS Lemmermann, iSgSc, p. 29. 



Cells mostly solitary, very long in proportion to the diameter, 

 with many pyrenoids in a single series ; otherwise as in 

 A nkistrodesm us. 



C. LONGISSIMA (Schroder) Lemmermann, var. TROPICA W. & 

 G. S. West, 1904, p. 31, PI. I, fig. i. Cells mostly solitary, 

 225-370 X 6-7.5 /i, slightly curved, tapering gradually to the 

 slender but subtruncate ends. Fig. 8. Wis., G. M. Smith. 



Europe. 



The typical form of C. longissima t not yet reported here, has 

 tips tapering to an extreme fineness, and is usually more curved. 



QUADRIGULA Printz, 1915, p. 49. 



Cells cylindric-fusiform, straight or slightly curved, apices 

 more or less acuminate, without pyrenoid ; vegetative reproduc- 

 tion by division of cell in two planes at right angles to each 

 other at the longitudinal axis of the cell, the four daughter 

 cells remaining enclosed in a gelatinous mass, which as a result 

 of successive divisions may contain as many as 128 cells. Only 

 one species. 



Q. CLOSTERIOIDKS (Bohlin) Printz, 1915, p. 49, PI. IV, figs. 

 110-116; Nfphrocytium dosterioides Bohlin. 1897, P- 18, PI. I, 

 figs. 23-24; Raphidium I*fit*eri Schroder, 1902, p. 152, PI. VI, 

 fig. 6 ; Ankistrodcsmus Pfitzeti G. S. West, 1904, p. 224, fig. 

 94. G. Cells 12-30 X i. 5-3.7 M- Fig- 9- Wis., G. M. Smith : 

 New Buffalo, Mich., Transeau. Europe. 



The cells are in shape much like those of Ankistrodcsmus. but 

 in the latter the cell division is by an oblique wall. In .-/. lartts- 

 tris, in which the daughter cells remain enclosed in a gelantinous 

 body of definite form, they are in no definite order, while in 

 Quadrigula the four daughter cells merely separate but remain 

 parallel. In a subsequent division all cells in the colony par- 

 ticipate, so that however large the number of cells, they continue 

 symmetrically placed. 



