116 MR, С. S. WEST ON THE FRESHWATER ALG 
69. Cosmarium PuasEoLvs, Bréh. in. Menegh. Synops. Desm. (1840) p. 220; 
Ralfs, Brit. Desm. (1848) p. 106, t. 32. fig. 5. | 
A form approaching var. elevatum, Nordst. 
Nyasa.—Among Algæ on the shore, Domira Bay (19 June, 1904; no. 17). 
70. Cosmarium BIOCULATUM, Breb. in Ralfs, Brit. Desm. (1848) p. 95, 
t. 15. fig. 5; W. $ G. S. West, Brit. Desm. ii. (1905) p. 165, t. 61. figs. 8-7. 
Forms with a punctate cell-wall, some individuals approaching var. hians, 
W. & G. В. West: long. 19-21 ш; lat. 16-18 4; lat. isthm. 4:5-6 p. 
Victoria Nyanza.—A mong Utricularia, near Bukoba (20 Apr. 1905; no. 618. 
71. ? CosMARIUM MINUTISSIMUM, Arch. in Quart. Journ. Міст. Set. xvii. 
(1877) pp. 194 and 301. 
Long. 11 р; lat. 9 ш; lat. isthm. Эш; crass. 55 p. 
Victoria Nyanza.—Among Utricularia, near Entebbe (1 May, 1905; по.620). 
It is with much doubt that I refer this minute Cosmarium to C. minutissimum, 
Arch., a species concerning which very little is definitely known. Another 
African form, from Huilla, Angola, W. Africa, has also been with uncertainty 
regarded as C. minutissimum (vide W. & С. S. West, in Journ. Bot. xxxv. 
(1897) p. 38). The sinus of the Nyanza specimens was not “a narrow 
incision " as deseribed by Archer, and the outline of the cell was exactly 
similar to that exhibited by some forms of C. contractum, var. ellipsoideum. 
72. Cosmartum CONTRACTUM, Airchn. Alg. Schles. (1878) p. 47; Wolle, 
Desm. U.S. (1884) p. 68, t. 50. fig. 24; W. ў G. S. West, Brit. Desm. ii. 
(1905) p. 170, t. 61. figs. 23-25, 34. 
Var. ELLIPSOIDEUM, (Elfe) W. & G. S. West, in Trans. Roy. Irish Acad. 
xxxii. part i. (1902) p. 40.—С. ellipsoideum, fv. 
Victoria Nyanza.—In plankton, Bukoba (18 Apr. 1905; no. 249). In 
sheltered bay near Entebbe (1 May, 1905; no. 620). 
13. CosMARIUM DEPRESSUM, (№49.) Lund. in Мог. Act. Reg. Soc. Sci. Upsal. 
ser. 3, viii. (1871) p. 38; И’. & б. 5. West, Brit. Desm. ii. (1905) р. 176, 
t. 62. figs. 2-5. —C. Scenedesmus, Delp. 
Victoria Nyanza.—In plankton, Bukoba (18 Apr. 1905 ; no. 249). 
Tanganyika.—In swamp, Mbete (28 Sept. 1904 ; no. 108). 
14. CosMARIUM RETUSIFORME, ( Wille) Gutw. in Bot. Centralbl. xliii. (1890) 
p. 69.—C. Hammeri, Feinsch, var. retusiforme, Wille. 
Forma ABscmsUuM (Schmidle), Borge, in Arkiv för Bot. К. Sv. Vet.- Akad. 
i. (1903) p. 96, t. 3. fig. 19.—C. Hammeri, Reinsch, f. abscissa, Schmidle, in 
Hedwigia, xxxiv. (1895) p. 302, t. 4. fig. 8. 
Long. 22-31 ш; lat. 17-22 р; lat. аріе. 9°5-13°5 p ; lat. isthm. 5-675 д. 
Victoria Nyanza.—Near Bukoba (20 Apr. 1905 ; по. 618). In sheltered 
bay near Entebbe (1 May, 1905; no. 620). 
