174 MR. С. S. WEST ON THE FRESHWATER ALGE 
Victoria Nyanza.—On rocks, Bukoba (17 Apr. 1905 : no. 248). 
Tanganyika.—On rocks in shallow water, Mbete (29 Sept. 1904 ; no. 114). 
307. LYNGBYA JERUGINEO-CGRULEA, (Atitz.) Gomont, Ann. Sci. Nat. 7° sér., 
Bot. xvi. (1892) p. 146, t. 4. figs. 1-3. 
Tanganyika.—On rocks, Niamkolo Harbour (7 Sept. 1904 ; по. 87). 
308. Lynepya Kürziwan, Sehmidle, in Allgem. Bot. Zeitschr. iii. (1897) 
р. 98.—Leibleinia Martensiana, Kätz. Tab. Phye. 1. р. 45, t. 82. fig. 1. 
Lyngbya Martensiana, Rabenh. Fl. Europ. Alg. ii. (1865) p. 143. 
Var. DISTINCTA, (Vordst.) Lemm. in Engl. Bot. Jahrb. xxxiv. (1905) 
р. 620.—L. Martensiana, В. distincta, .Vordst. Aly. Sandvic. p. 4. L. subtilis, 
West, in Journ. Roy. Mier. Soc. (1892) p. 741, t. 10. fig. 58. L. distincta, 
Schmidle, L e. 
Victoria Nyanza.—Among Utricularia, swampy pool near Bukoba (20 Apr. 
1905 ; no. 618) and in sheltered bay near Entebbe (1 May, 1905 ; no. 620). 
309. LYNGBYA CIRCUMCRETA, sp. п. (PI. 9. fig. 7.) 
L. filis solitariis pelagiis et brevibus, spiraliter contortis ; spiris latis et 
arctissimis, anfractibus adnatis 2-9 (plerumque 2-23); vaginis tenuibus, 
firmis, arctissimis et achrois; cellulis subquadratis vel diametro brevioribus, 
cytoplasmate pallide rugineo et homogeneo ; cellula apicali rotundo- 
truncata, 
Crass. cell. 1:8-21 u; long. cell. 1-2 р; diam. anfract. 28—44 p. 
Victoria Nyanza.—In plankton, near Bukoba (April 1935 ; nos. 249 and 
252). Also in sheltered bay near Entebbe (1 June, 1905 ; no. 620). 
This species occurred floating in the plankton as closely coiled threads which 
have the appearance of small hoops. The filament grows in the manner of 
a flat spiral, the twists of the spiral being wide but very close together. 
[t is nearest to L. contorta, Lemm., but differs in the hoop-like coiling of 
its filaments, which are also of greater thickness, and in the much shorter 
cells. The coils of L. circumereta are much wider than those of L. contorta 
and more exactly circular. 
310. LyNGBYA PURPUREA, Gomont, l, c. (1892) p. 149.— Oscillatoria pur- 
purea, Hook. f. & Harv. 
Crass. trich. 1*7 д. 
Tanganyika.—A mong Calothrix cartilaginea, sp. n., on inside of canoe 
(6 Jan. 1905 ; no. 205). 
311. LYNGBYA BIPUNCTATA, Lemm. in Forschungsh. Biol. Stat, Plön, vi. 
(1900) p. 138, t. 2. fig. 48; l е. x. (1903) p. 152. 
а. Crass. trich. 1-4-1:5 р; long. cell. 3:5-5*5 р. 
Nyasa.—In plankton, near Mtangula (22 June, 1904; по. 20), and off 
