144 MR. G. 5. WEST ON THE FRESHWATER ALGZE 
cells attained slightly larger dimensions than those described by Lemmermann 
from Germany. The three spine-like bristles at each pole were frequently 
bent and usually widely spreading. 
Subfam. DicrTvYosPHERIEA. 
Genus DICTYOSPHJERIU M, Nag. 
180. DicryosPH&RIUM PULCHELLUM, Wood, Freshw. Alg. U. S. (1814) p. 84, 
t. 10. fig. 4. 
Nyasa.—In plankton, Anchorage Вау (11 June, 1904 ; no. 5). 
Tanganyika.—In plankton, near Chumkaluki (15 Nov. 1904 ; no. 160) and 
near Kala (19 Nov. 1904 ; no. 170). 
Victoria Nyanza.—In plankton, near Bukoba (18 Apr. 1905; no. 249). 
In swampy pool near Bukoba (20 Apr. 1905 ; no. 618). 
Genus TETRACOCCUS, West. 
181. TETRACOCCUS: BOTRYOIDES, West, in Journ. Roy. Мет. Soc. (1892) 
р. 735, t. 10. figs. 43-48. 
Diam. colon. 56-84 ш; diam. cell. 4—8 д. 
Tanganyika.—In plankton, off Niamkolo Island (29 July, 1904 ; no. 36), 
Komba Bay (11 Oct. 1904; no. 135), and near Kala (19 Nov. 1904; 
по. 170). 
Genus BOTRYOCOCCUS, Кш. 
152. Borryococous Braunu, Aütz. Sp. Alg. (1849) p. 892; Rabenh. FL 
Ёитор. Aig. 111. (1868) р. 42, fig. 14; Chodat, in Morot, Journ. de Bot. x. 
(1896) p. 303, t. 3. 
Nyasa.—In plankton, Monkey Bay (17 and 18 June, 1904; поз. 15 and 16); 
also off Vahambwera Point (24 June, 1904 ; no. 24) and off Karonga (1 July, 
1904 ; no. 30). 
Tanganyika.—In plankton, Utinta (5 Dec. 1904 ; по. 181). 
Victoria Nyanza.—In plankton, near Bukoba (20 and 21 Apr. 1905; 
nos. 250 and 252). 
The large colonies of this Alga formed in some instances a yellow scum on 
the surface of the water. This was due to the appearance of the brick-red 
pigment which at certain seasons gives the colonies a decided yellow or 
yellowish-red colour and causes a corresponding coloration of the water. 
Genus INEFFIGIATA, W. d G. S. West. 
183. INEFFIGIATA NEGLECTA, W. § @. S. West, in Journ. Roy. Micr. Soc. 
(1897) p. 508; W. & G. S. West, in Journ. Bot. xli. (1903) p. 80, t. 447. 
figs. 1-6. 
Victoria Nyanza.—In plankton, near Bukoba (21 Apr. 1905 ; no. 252), 
