108 MR. G. S. WEST on THE FRESHWATER ALGJE 
Subfam. PLACODERM. Ж. 
Genus PENIUM, Bréb. 
30. PENIUM NavicuLA, Bréb. in Мет. Soc. Sci. Nat. Cherb. iv. (1856) p. 146, 
t. 2. fig. 37; W. & С. S. West, Brit. Desm. i. (1904) p. 75, t. 7. figs. 12-15. 
Victoria Nyanza.—In swampy pool near Bukoba (20 Apr. 1905; no. 618). 
31. PENIUM AUSTRALE, Racib. in Rospraw. matem.-przy. Akad. Umiej. 
Krakow. ser. 2, xxii. (1892) p. 367, t. 6. fig. 27; W. 4 G. S. West, in 
Journ. Linn. Soc., Bot. xxxiii. (1897) p. 157, t. 8. fig. 16; in Bot. Tidsskr. 
xxiv. (1901) р. 163. 
a. Forma brevior: long. 55-57 р; lat. 36-38 ш; lat. isthm. 35-36 д. 
(РІ. 6. fig. 3.) 
Victoria Nyanza.—Near the shore, Bukoba (20 Apr. 1905 ; no. 251). 
6. Forma crassior: long. 72 p ; lat. 51 ш: lat. isthm. 48 p. (РІ. 6. fig. 4.) 
Victoria Nyanza.—In swampy pool near Bukoba (20 Apr. 1905; no. 618 ) 
Genus CLOSTERIUM, Nitzsch. 
32. CLOSTERIUM LAGOENSE, Nordst. т Vidensk. Medd. f. d. Naturh. Foren. 
Кудр. (1870) р. 208, t. 2. fig. 2. 
Tanganyika.—In swamp, Mbete (28 Sept. 1904 ; по. 108). 
33. OLOSTERIUM NEMATODES, Josh. in Journ. Linn. Soc., Bot. xxi. (1886) 
р. 652, t. 22. figs. 7-9. 
Var. томом, var. п. (PI. 6. fig. 2.) 
Var. cellulis paullo tumidis ad medium marginis ventralis, polis obtusioribus, 
striis validioribus. 
Long. 190 ш; lat. 27 ш; lat. apie. 10 м. 
Victoria Nyanza.— Near the shore of the lake, Bukoba (20 Apr. 1905 ; 
no. 251). 
The apices of this variety are more obtuse than in the typical form, and 
the ventral margin of the cell is distinctly tumid, giving it a stouter 
appearance. 
34. CLOSTERIUM PARVULUM, Ndg. Gatt. einz. silg. (1849) p. 106, t. 6c. 
fig. 2 (ex parte); W. & G.S. West, Brit. Desm. i. (1904) p. 133, t. 15. 
figs. 9-12. 
Small forms: lat. 11 р; apicibus 105 и inter se distantibus. 
Nyasa.— In swamp, Karonga (2 July, 1904 ; поз. 33 and 34). 
Victoria Nyanza.—In swamp pool near Bukoba (20 Apr. 1905; no. 618). 
39. CLosrERIUM JENNERI, Ralfs, Brit. Desm. ( 1848) p. 167, t. 28. fig. 6 ; 
W. & G. S. West, l. c. p. 134, t. 15. figs. 28—25. 
Lat. 11-13 p ; apicibus 82-91 y inter se distantibus. 
Victoria Nyanza.—In pools near the shore, Bukoba (20 Apr. 1905; no. 251). 
