OF THE THIRD TANGANYIKA EXPEDITION, 105 
Genus SPIROGYRA, Link. 
19. SPrROGYRA sp. ad ©. longatam, (Vauch.) Мг. accedens. 
The zygospores were not mature and the specimens were scarcely in a 
condition for accurate description. 
Crass. cell. veget. 34-38 ш; long. zygosp. immatur. 72 р, lat. 53 д. 
Nyasa.—In swamp, Karonga (2 July, 1904 ; no. 33). 
20. SPIROGYRA PORTICALIS, ( Vauch.) Clevejin Nov. Act. В. Soc. Sci. Upsal. 
ser. д. vi. no. 11 (1868), р. 22; Petit, Spirog. Environs Paris (1880), p. 21, 
t. 5. figs. 8-12. 
Var. AFRICANA, Var. n. 
Var. cellulis fructiferis leviter tumidis; cellulis vegetativis et chromato- 
phoris singulis ut in forma typica; zygosporis paullo majoribus, oblongo- 
ellipticis, mesosporio plicato-ruguloso. 
Crass. cell. veget. 40-41 u; long. zygosp. 93 р, lat. 58 p. 
Nyasa.—Among weeds and various Algæ, in swamp, Karonga (2 July, 
1904 ; no. 34). 
21. SPIROGYRA AQUINOCTIALIS, sp. п. (РІ. 5. figs. 1-2.) 
S. cellulis vegetativis diametro circiter 4—6-plo longioribus, extremitatibus 
. non replicatis ; chromatophoris 3 (interdum 2), suberassis, marginibus irregu- 
lariter undulatis, anfractibus 1-12, cum pyrenoidibus magnis; conjugatione 
scalariformi, cellulis fructiferis inflatis et suboblongo-rectangularibus ; zygo- 
sporis oblongo-ellipticis, ovoideis, vel oblongo-ovoideis, diametro circiter 
1}-14-plo longioribus ; membrana zygosporz crassa, lamina mediana dense 
scrobiculata. 
Crass. cell. veget. 23-25 д; crass. cell. fructif. ($) 41°5-43 ш; long. 
zygosp. 52-71 р, lat. 41-43 д; crass. membr. zygosp. 4 д. 
Nyasa.—Growing on stones, &c., on the shore, Domira Bay (19 June, 1904; 
no. 17). 
The zygospores are mostly oblong-elliptic in form, with brown walls of 
considerable thickness, the middle coat of which is densely and markedly 
scrobiculate. They fill up the fructiferous cells transversely, being closely 
applied to the swollen walls of the female gametangia. ‘The chloroplasts are 
most commonly three (sometimes only two) in each cell, with nodulose or 
undulate margins and large pyrenoids. 
It stands nearest to another tropical species, 5. соти, W. & G. S. West 
(Freshw. Alg. Koh Chang, in Bot. Tidsskr.. xxiv. (1901) p. 161, t. 4. figs. 
48—45), but is distinguished by its thinner vegetative filaments with shorter 
cells, by the shorter and more oblong zygospores, and by the oblong form of 
the inflated fructiferous cells. 
