Smith—Monograph of Scenedesmus. 
441 
cells have the characteristic concavity on the side towards 
the colony and the convexity on the other side. In my pure 
cultures, I have found the cells arranged in a linear series, 
but no marked alteration in them, while the terminal bulb 
is not very pronounced. The cells are much smaller than 
those of Bohlin, the largest measuring but 12 x 4.5 g. The 
differences in both shape and size of the cells warrants the 
establishing of a new variety. 
8. S. bijuga (Turp.) Lag. (PI. XXV: Fig. 2.) 
Lagerheim, 1893, p. 158. Lagerheim, 1900, p. 10. Borge, 
1907A, p. 57. Borge, 1907B, p. 4. Collins, 1909, p. 168. Hayden, 
1910, p. 44. Klugh, 1911, p. 97. Klugh, 1912, p. 115. Borge, 
1913, p. 60. 
Achnanthes bijuga. Turpin, 1828, p. 310; PI. XIII, Fig. 4. 
Achnanthes quadrijuga. Turpin, 1820, Fig. 6. Turpin, 1828, 
p. 310; PI. XIII, Fig. 5. 
Achnanthes quadralterna. Turpin, 1820, Fig. 8. Turpin, 1828, 
p. 311; PI. XIII, Fig. 7. 
Achnanthes octalterna. Turpin, 1820, Fig. 12. Turpin, 1828, 
p. 312; PI. XIII, Fig. 8. 
Bacillaria viridis. Leiblein, 1830, p. 316; Pi. I, Fig. 3. 
S. obtusus. Meyen, 1829, p. 775; PI. XLIII, Figs. 30-31. 
Meneghini, 1840, p. 209. Hassall, 1845, p. 393; PI. XCII, Fig. 15. 
Ralfs, 1845,,p. 404; PI. XII, Fig. 8. Ralfs, 1846, p. 162; PI. XV, 
Fig. 8. Ralfs, 1848, p. 193; PI. XXXI, Figs. 16A-16C. Bailey, 
1851, p. 29. Bailey, 1855, p. 12. Griffith and Henfrey, 1856, p. 
656; PI. X, Figs. 53-54. Archer, 1857, p. 40. Zanardini, 1857, 
p. 250. Grunow, 1858, p. 499. Reinsch, 1867, p. 80. Rabenhorst, 
1868, p. 63; Figs. 34D-34E. Hohenbuhel-Heufler, 1871, p. 318. 
Rostrop, 1871, p. 90. Olney, 1872, p. 135. Wittrock, 1872, p. 31. 
Archer, 1874, p. 329. Wood, 1874, p. 90. Kirchner, 1878, p. 98. 
Oudemans, 1879. Wille, 1879, p. 30. Cienowsky, 1881, p. 304. 
Wolle, 1881, p. 213. Cooke, 1882, p. 33; PI. XIII, Fig. 5, Nord- 
stedt, 1882, p. 46. Spencer, 1882, p. 296. Griffith and Henfrey, 
1883, p. 679; PI. XIV, Figs. 53-54. Artari, 1884, p. 132. Hansgirg, 
1884A, p. 9. Boldt, 1885, p. 97. Griffith and Henfrey, 1885, p. 686; 
PI. X, Figs. 53-54. Paque, 1885, p. 52. Parfitt, 1886, p. 392. 
Beck, 1887, p. 274. Bennett, 1887, p. 9. Martel, 1887A, p. 340. 
Martel, 1887B, p. 11. de Toni et Levi, 1887, p. 1584. Alexenko, 
1888, p. 158. Balsamo, 1888, p. 40. Bennett, 1888, p. 2. Harvey, 
1888, p. 157. Konig,1888, p. 89. Loitlesberger, 1888, p. 224. 
Nordstedt, 1888, p. 19. W. West, 1888, p. 748. Heiden, 1889, 
p. 5. Riabinine, 1889A, p. 302. Riabinine, 1889B, p. 46. de 
Toni, 1889A, p. 70. Webber, 1889, p. 1012. W. West, 1889A, p. 
290. Andersson, 1890, p. 5. Chmielweski, 1890, p. 92. Roy 
1890, p. 338. W. West, 1890, p. 298. de Wildemann, 1890B, p. 
