106 MR. С. S. WEST ON THE FRESHWATER ALG.E 
22. SPIROGYRA  DECIMINA, (Müll) Kiti. Рус. Germ, (1845) p. 223; 
Rabenh. Fl. Europ. Alg. iii. (1868) р. 242; Petit, Spirog. Ene. Paris, 1880, 
р. 25, t. 8. figs. 1-8. 
Crass. cell. veget. 32-36 р; long. zygosp. 65-68 ш; lat. zygosp. 37-39 д. 
Nyasa.—In swamp, Karonga (2 July, 1904 ; nos. 32 and 33). 
Forma cellulis crassioribus et zygosporis sepe diametro duplo longioribus. 
Crass. cell. veget. 42-54 ш; long. zygosp. 68-124 ш; lat. zygosp, 47—50 и. 
Nyasa.—In swamp, Karonga (29 June, 1904 ; по. 32). 
Forma ТЕОР1СА [.S. decimina, forma, W. & G. S. West, in Bot. Tidsskr. 
xxiv. (1901) р. 161]. 
Forma major, cellulis vegetativis diametro 21—5(usque 6)-plo longioribus ; 
cellulis fruetiferis non inflatis ; chromatophoris 3, eum marginibus asperis, 
anfractibus 24—44. 
Crass. cell. veget. 46-52 р; long. zygosp. 72-92 ш; lat. zygosp. 46-50 д. 
Nyasa.—In pools on the shore, Nkata Bay (23 June, 1904 ; no. 22). 
Tanganyika.—In swamp, Kituta (26 Aug. 1904 ; no. 80). 
Precisely the same form has been observed from Koh Chang in the Gulf 
of Siam. 
Very near to these tropical forms of 5. decimina, and most probably iden- 
tical with them, is a species described by Schmidle as S. Füllebornei (vide 
Engl. Bot. Jahrb. xxxii. (1903) p. 76, t. 3. fig. 2). The thickness of the 
vegetative cells is the same, there are three spirals in each case, and the size 
and form of the zygospores are the same. Schmidle’s plant was described 
from the vicinity of Nyasa. 
23. SPIROGYRA NEGLECTA, (Назз.) Kütz. Sp. Alg. (1849) p.441; Rabenh. 
lie, p. 248; Petit, l. с. p. 26, t. 9. figs. 1-5.—Zygnema neglecta, Hass. 
Var. TERNATA, (Ripart) И’. у (+. S. West, т Journ. Bot. xxxv. (1897) 
р. 41.— №. ternata, /братЬ in Bull. Soc. Bot. Fr. xxiii. (1876) p. 162; Petit, 
l. c. p. 26, t. 8. figs. 4—7. 
Crass. cell. veget. 52-59 ш; long. zygosp. 74-78 ш; lat. zygosp. 52-53 и. 
Tanganyika.—In swamp, Mrumbi (27 Dec. 1904 ; no. 196). 
24. SPIROGYRA NITIDA, (Dillw.) Link, Handb. iii. (1833) p. 262; Kütz. 
[. с. р. 442; Petit, l. c. p. 28, t. 10. figs. 6—10. 
Crass. cell. veget. 80-85 ш; long. zygosp. 105-148 ш; lat. zygosp. 55-84 д. 
Муаза.— [п swamp, Karonga (2 July, 1904 ; no. 33). 
25. SPIROGYRA BELLIS, ( Hass.) Cleve, т Nov. Act. В. Soc. Sci. Upsal. ser. З, 
vi. no. 11 (1868), p. 18 ; Petit, l. v. р. 91, t. 10. figs. 1-8. 
Var. MINOR, var. n. 
Var. cellulis angustioribus et zygosporis minoribus. Crass. cell. veget. 
56-58 м; diam. zygosp. 44—56 д. 
Tanganyika.—In swamp, Mrumbi (27 Dec. 1904; no. 196). 
