462 Wisconsin Academy of Sciences, Arts, and Letters. 
18. S. carinatus (Lemm.) Chodat. (PL XXVI: Fig. 25.) 
Chodat, 1913, pp. 23, 69. 
S. opoliensis var. carinatus. Lemmermann, 1899, p. 113; PL I, 
Fig. 7. Marsson, 1901 A, pp. 90, 101, 115. Marsson, 1901B, p. 96. 
Lemmermann, 1904A, pp. 8, 20, 84, 158. Lemmermann, 1904C, 
p. 159. Lemmermann, 1905B, p. 163. Migula, 1907, p. 655. Selk, 
1907, p. 79. Lemmermann, 1908G, p. 357. Marsson, 1911, pp. 
263, 265, 286. Brunnthaler, 1913, pp. 169, 171; Fig. 20. 
Coenobia 4-cellularum. Cellulis fusiformibus, membrana 
longitudinaliter costata in utroque parte atque in utroque 
polo 2-3 denticulis parvis instructis. Omne cellulae ter- 
minale cum longo curvato aculeo atque dentibus in utroque 
polo. 
The cells of this form possess the characteristic shape of 
S. opoliensis Richt., but there is a distinct longitudinal ridge 
on each side of every cell. Since cultural work on such 
forms shows that this longitudinal ridge is a constant char¬ 
acter, and since the strains of S. opoliensis isolated do not 
show any, this form should be regarded as a distinct species. 
GEOGRAPHICAL DISTRIBUTION 
Germany (Lemmermann, 1899, 1905B; Marsson, 1901 A, 1901B, 
1911; Selk, 1907). Italy (Lemmermann, 1908G). Java (Lemmer¬ 
mann, 1904C). Sweden (Lemmermann, 1904A). 
19. S. hystrix Lag. (Pl. XXVI: Fig. 35.) 
Lagerheim, 1882, pp. 62, 65; PL II, Figs. 18. Lagerheim, 1886, 
p. 45. Lagerheim, 1887, p. 194. de Toni, 1889B, p. 565. de 
Wildemann, 1893A. de Wildemann, 1893B, p. 91. de Wilde- 
mann, 1895, p. 26. Bohlin, 1897, p. 22. Schroder, 1897A, p. 372. 
Schroder, 1897B, p. 487. Schroder, 1897G, p. 45. de Wildemann, 
1897B, p. 50. Schroder, 1898, p. 23. Garbini, 1899A, p. 15. Lem¬ 
mermann, 1899, p. 112. Schroder, 1899, p. 22. Balsamo, 1900, 
p. 266. Chodat, 1901, p. 1309. West and West, 1901B, p. 121. 
Forti, 1902, p. 60. West and West, 1902B, p. 64. Boergesen 
and Ostenfeld, 1903, p. 615. Fournier, 1903, p. 28. Volk, 1903, 
p. 103. Gozette, 1904, p. 273. G. S. West, 1904B, p. 221. West 
and West, 1904, p. 221. West and West, 1904, p. 531. Huber, 
1905, p. 57. Lemmermann, 1905B, pp. 158, 160. Reinhardt, 
1905, p. 26. Suhr, 1905, p. 253. Fritsch, 1906, p. 205. Pascher, 
1906, p. 168. Brunnthaler, 1907, p. 207. Lemmermann, 1907B, 
p. 112. Teodoresco, 1907, p. 130. Adams, 1908, p. 35. Huber, 
1908, p. 314. Lemmermann, 1908A, p. 167. Lemmermann, 1908C, 
p. 357. Collins, 1909, p. 169. West and West, 1909B, p. 184. 
