434 Wisconsin Academy of Sciences , Arts, and Letters. 
1904G; de Wildemann, 1897C, 1899). Johore (Bernard, 1909). 
New Zealand (Lemmermann, 1900G; Nordstedt, 1888, Spencer 
1882). 
AMERICAS. Argentina (Borge, 1899, 1907B; Nordstedt, 1882; 
Wille, 1884). Barbados (G. S. West, 1904). Brazil (Bohlin, 1897; 
Wille, 1884). Canada (Borge, 1909; Klugh, 1911; MacKenzie, 
1899). Pategonia (Borge, 1901B; Nordstedt, 1882). Paraguay 
(Bohlin, 1897). United States (Andrews, 1909; Bailey, 1851; 
1855; Borge, 1909; Buchanan, 1907; Campbell, 1886; Collins, 1909; 
Conn and Webster, 1908; Ehrenberg, 1843; Fanning, 1901; Fink, 
1905; Hayden, 1910; Kofoid, 1910; Riddle, 1902; Snow, 1903; 
Stokes, 1893; Tilden, 1898; W. West, 1889B; Wood, 1869; 1874; 
Wolle, 1881, 1887). 
POLAR AND SUB-POLAR REGIONS. Boergesen, 1899A. 
Faeroes (Boergesen, 1899B, 1901A). Greenland, (Larsen, 1907A; 
Lauterborn, 1905). KergueVs Land (Reinsch, 1876). 
3. S. dimorphus (Turp.) Ktz. (PI. XXV: Fig. 8. PI. 
XXXII: Figs. 185-189. PI. XXXIII: Figs. 190-195.) 
Kiitzing, 1833, p. 608. de Brebisson, 1839, p. 271. Meneghini, 
1840, p. 208. Hassall, 1845, p. 393; PL XCII, Fig. 13. Ralfs, 
1845, p. 403; PI. XII, Fig. 5. Ralfs, 1846, p. 160; PI. XV, Fig. 5. 
Ralfs, 1848, p. 191; PI. XXXI, Figs. 13A-13B. Grunow, 1858, p. 
499. Zanardini, 1857, p. 250. Kirchner, 1878, p. 98. Artari, 
1884, p. 133. Martel, 1887B, p. 11. Wolle, 1887, p. 173; PL 
CLVI, Figs. 18-21. Alexenko, 1888, p. 159. Heiden, 1889, p. 5. 
Riabinine, 1889B, p. 47. Webber, 1889, p. 1012. Chmielweski, 
1890, p. 92. Alexenko, 1891, p. 62. Lemmermann, 1891, p. 148. 
Harvey, 1892, p. 119. . Weiss, 1892, p. 37. Franze, 1893, p. 286. 
Jeliffe, 1893A, p. 243. Jeliffe, 1893B, p. 605; PL III, Fig. 35. 
Schroder, 1893, p. 72. Stokes, 1893, p. 51. Alexenko, 1894, p. 
72. Jeliffe, 1894, p. 594. Alexenko, 1895, p. 92. Zacharias, 1898, 
p. 93. Iwanoff, 1899, p. 379. Jeliffe, 1899, p. 5. Balsamo, 1900, 
p. 266. Forti, 1902, p. 60. Snow, 1903, p. 391. Zacharias, 
1903A, p. 213. Comere, 1904, p. 62. Moreto, 1904, p. 440. 
Skorikow, 1905, p. 10fL Quelle, 1908, p. 43. Andrews, 1909, p. 
379. Comere, 1911, p. 50. 
Achnanthes dimorpha. Turpin, 1820, Fig. 2. Turpin, 1828, p. 
313; PL XIII, Fig. 12. 
Scenodesmus dimorphus. Kiitzing, 1849, p. 186. de Brebisson, 
1856, p. 159. Conn and Webster, 1908, p. 35; PL IV. Fig. 42. 
S. acutus var. dimorphus. Rabenhorst, 1868, p. 64; Fig. 34i. 
Cooke, 1882, p. 34; PL XIII, Fig. 6. de Wildemann, 1885, p. 123. 
Parfitt, 1886, p. 392. Beck, 1887, p. 274. Andersson, 1890, p. 5. 
W. West, 1891A, p. 248. W. West, 1892A, p. 194. W. West, 
1892B, p. 738. Borge, 1894, p. 9. Fritsch, 1902, p. 582. Fritsch, 
1903, p. 646. Fritsch, 1906, p. 205. 
S. obliquus var. dimorphus. Hansgirg, 1886, p. 116. de Toni, 
1889B, p. 567. Hansgirg, 1890A, p. 112. Lemmermann, 1893, p. 
