1907] Cushman,— New England Species of Penium 231 
PENIUM SPIROSTRIOLATUM Barker. 
Penium margaritaceum, var. punctatum Ralfs, Brit. Desm., 1848, 
p. 149, pl. 25, figs. 1, d-h. 
Penium spirostriolatum Barker, in Quart. Journ. Micr. Sci., vol. 9, ` 
1869, p. 194; Wolle, Freshw. Alg. U. S., 1887, p. 22, pl. 61, fig. 19; 
G. S. West, Journ. Linn. Soc. Bot., vol. 34, 1899, p. 377-380; W. & 
G. S. West, Brit. Desm., vol. 1, 1904, p. 88, pl. 9, figs. 1-8. 
Cells large, about 9 times as long as wide, cylindrical, with a slight 
median constriction, slightly attenuated toward the rounded apices, 
transverse sutures apparent, cell wall yellowish brown, marked with 
longitudinal striae, variably twisted especially near the ends of the cell. 
Length 202-233 p; breadth 19-25 u; apex 15-16 p. 
Me.: Orono (W. West); Mass.: Winchester! Lake Watuppa, 
Fall River! 
* PENIUM SPIROSTRIOLATUM, var. apiculatum var. nov. 
Cells about four times as long as wide, central portion cylindrical, , 
at each end very abruptly narrowed for about one-sixth of the length. 
Length 84 u; breadth 21 5; apices 11.5 y. 
Mass.: Plymouth! 
PENIUM POLYMORPHUM Perty. 
Closterium polymorphum Perty, in Bern. Mitth. 1849, p. 28. 
Penium polymorphum Perty, Kleinist Lebensf., 1852, p. 207; Wolle, 
Desm. U. S., 1884, p. 36, pl. 5, fig. 12; W. & G.S. West, Brit. Desm., 
vol. 1, 1904, p. 90, pl. 9, figs. 9-11. 
Cells small, about 23 times as long as wide, cylindrical with a slight 
median constriction, very slightly attenuated toward the broadly 
rounded apices, cell-wall with inconspicuous, longitudinal striations. 
Length 50 x; breadth 20 u. 
-Vt.: Charlotte (Wolle); N. H.: Pudding Pond, North Conway, 
occasional! Mass.: Amherst (W. West). 
PENIUM PHYMATOSPORUM Nordst. 
Penium phymatosporum Nordst., Desm. Ital., 1876, p. 26, pl. 12, 
fig. 1; W. & G. S. West, Brit. Desm., vol. 1, 1904, p. 91, pl. 6, figs. 
9-11. 
