154 MR. G. $. WEST ON THE FRESHWATER ALGÆ 
Tanganyika.—In plankton, near Sumbu (13 Oct. 1904 ; no. 138) and near 
Kalambo (5 Nov. 1904 ; по. 154). Among various Algæ scraped from the 
inside of canoe (6 Jan. 1905 ; no. 205). 
214. NAvICULA PuruLA, Kütz. Вас. (1844) р. 93 ; Van Heurck, Synops. 
Diat. Belg. p. 106, t. 13. figs. 15, 16; Cleve, Synops. Navic. Diat. i. (1894) 
p. 131. 
Tanganyika.—In plankton, Kituta Bay (26 Aug. 1904; по. 81), near 
Kalambo (5 Nov. 1904 ; no. 154), near Kala (19 Nov. 1904 ; no. 170), off 
Kirando (1 Dec. 1904; no. 175), and near Baraka (24 Feb. 1905; 
no. 240). 
215. NAVICULA mutica, Kitz. l.c. t. 3. fig. 32 ; Cleve, Synops. Navic. Diat. 
i. (1894) p. 129. 
Forma valvis leviter tumidis ad medium utrobique. 
Long. valv. 30-34 ш; lat. ad med. 13-14 y. 
Nyasa.—In plankton, Anchorage Вау (13 June, 1904 ; nos. 9 and 10). 
216. Navicuta Crucicuna, ( W. Sm.) Donkin, Brit. Diatomacee, p. 44, t. 6. 
fig. 14 ; Cleve, Synops. Navic. Diat. i. (1894) p. 139.—8Stauroneis Crucicula, 
W. Sm. 
Nyasa.—In plankton, Anchorage Bay (11 June, 1904 ; no. 5). 
217. NAVICULA BAHUSIENSIS, Grun. Diat. Franz-Jos.-land, p. 51 (1880) ; 
Cleve, Synops. Navic. Diat. ii. (1895) p. 4. 
Nyasa.—In plankton, Anchorage Вау (13 June, 1904 ; no. 9). 
Tanganyika.—In plankton, off Kirando (1 Dec. 1904 ; no. 175). 
This Diatom has previously been recorded only as a marine species, but is 
regarded by Van Heurck as a variety of JN. minuscula, Grun., which is of 
freshwater habit. 
218. NavICULA ($ ANOMGONEIS) зрн жворнова, Kitz. Васі. 1844, p. 95, 
t. 4. fig. 17. 
Nyasa.—On shores of lake, Domira Вау (19 June, 1904 ; по. 17). 
219. NAvICULA ($ ANoM@ONEIS) EXILIS, Kutz. l. c. ; Van Heurck, Synops. 
Dat. Belg. р. 101, t. 12. figs. 11, 12. 
Nyasa.—In swamp, Karonga (2 July, 1904 ; no. 34). 
220. NAVICULA CRYPTOCEPHALA, Kütz. І. c. t. 3. fig. 26; W. Sm. Brit. Diat. 
р. 53, t. 17. fig. 155. 
Tanganyika.—In swamp, Toa (10 Jan. 1905 ; no. 208). 
221. NAVICULA RADIOSA, Kütz. t. c. p. 91, t. 4. fig. 23. 
Victoria Nyanza.—In plankton, near Bukoba (18 Арг. 1905 ; no. 249). 
