150 МВ. G. S, WEST ON THE FRESHWATER ALGÆ 
199. Synepra ULNA, (Nitzsch) Ehrenb. Infus. (1838) p. 211, t. 17. fig. 1; 
Rabenh. Fl. Europ. Alg. i. (1864) р. 133. 
Nyasa.—Swampy lake margin, Domira Bay (19 June, 1904 ; no. 579). 
Tanganyika.—In plankton, Lofu River (5 Oct. 1904 ; по. 123). In swamp, 
Toa (10 Jan. 1905 ; no. 208). 
Victoria Nyanza.—In swampy pool, near Bukoba (20 Apr. 1905 ; no. 618). 
Var. SPLENDENS, (Kütz.) Van Heurck.—S. splendens, Aut. Baeill. (1844) 
р. 66, t. 14. fig. 16. 3. radians, W. Sm. Brit. Diat. i. p. 71. 
Tanganyika.—In plankton, Lofu River (5 Oct. 1904 ; поз. 123 and 124). 
200. SYNEDRA PULCHELLA, Kütz. Bacill. (1844) p. 68, t. 29. fig. 37; 
W. Sm. Brit. Diat. i. p. 10, t. 11. fig. 84. 
Tanganyika.—Floating on surface of water, Kituta Вау (26 Aug. 1904; 
по. 79). In swamp, Mbete (28 Sept. 1904 ; no. 108). 
Victoria Nyanza.— Among Utricularia, near Entebbe (1 May, 1905; no. 620). 
201. SvNEDRA Acus, Kütz. Вас. (1844) p. 68, t. 15. fig. 7; Rabenh, РІ. 
Еитор. Alg. i. (1864) p. 136. 
Nyasa.—Swampy lake margin, Domira Bay (19 June, 1904 ; no. 579). 
Tanganyika.—In plankton, near Kirando (1 Dec. 1904 ; no. 175). 
Victoria Nyanza.—In plankton, near Bukoba (21 Apr. 1905; no. 252). 
Among Utricularia, near Entebbe (1 May, 1905 ; no. 620). 
Var. nELICATISSIMA, ( W. Sm.) Grun.—S. delicatissima, W. Sm. 
Nyasa.—In plankton, Anchorage Bay (9 June, 1904; no. 2, and 13 June, 
1904; no. 9), and Monkey Bay (18 June, 1904 ; no. 16). 8. end of lake 
(15 June, 1904 ; no. 577). 
Tanganyika.—In plankton, off Niamkolo (29 July, 1904; no. 36, and 
9 Aug. 1904; no. 53). In swamp, Kituta (26 Aug. 1904; no. 80). In 
plankton, Mbete (28 Sept. 1904; no. 109), Komba Вау (11 Oct. 1904 ; 
по. 135), Vua Harbour (29 Oct. 1904 ; no. 150), near Kassanga (14 Nov. 
1904; no. 159), and near Chamkaluki (15 Nov. 1904; no. 160). "This 
variety was particularly abundant from no. 109. 
Victoria Nyanza.—In plankton, near Bukoba (21 Apr. 1905 ; no. 252). 
Var. ? (=Synedra revaliensis, Lemm. ex W. & G. S. West, т Trans. Roy. 
Irish. Acad. xxxiii. (1906) sect В, p. 110.) 
Long. 85-94 р; lat. 2-2°5 д. 
Tanganyika.—In plankton, near Kasawa, near Kirando (1 Dec. 1904 ; 
no. 175), near Utinta (5 Dec. 1904 ; no. 181), near Maswa (14 Jan. 1905 ; 
no. 211), in middle of lake between Rumonge and Uvira (30 Jan. 1905; 
по. 218), and near}Ndauvie (7 Feb. 1905 ; no. 221). 
I am not quite certain of this determination, as I have not seen a 
published description or figure of Lemmermann's species. [Since this 
was written Lemmermann's description of $. revaliensis has appeared in 
Ber. Deutsch. Bot. Ges. xxiv. (1906) p. 936.] It agrees, however, with 
