OF THE THIRD TANGANYIKA EXPEDITION. 171 
292. ANABANA TANGANYIKA, sp. п. (Pl. 10. fig. 3.) 
А. pelagica, trichomatibus brevissimis, spiraliter contortis anfractibus 1-2 
(plerumque cire. 11), evaginatis, inter cellulas non constrictis, utroque fine 
heterocysta terminatis ; cellulis cylindricis, diametro 2-3-plo longioribus 
(3:5-8:5 р longis), utroque polo truncatis ; cytoplasmate minute granulato, 
pallide wruginoso; heterocystis oblongo-ellipticis terminalibus ; sporis ellip- 
ticis, solitariis ?, ab heterocystis plerumque remotis, episporio levi et hyalino. 
Crass. trich. 2:4—2:0 ш; long. heterocyst. 5:5 р; lat. heterocyst. 3p; 
long. spor. 18 р, lat. 7 p. 
Tanganyika.—In plankton, near Baraka (24 Feb. 1905 ; no. 240). 
This species presents а similar modification of the trichomes to that shown 
by A. Flos-aque var. circularis. Each trichome is short and twisted into 
a spiral of rather more than one complete revolution, and each extremity is 
terminated by a heterocyst. Beyond this point, however, the resemblance 
ceases. А. Tanganyike is a very much narrower species, with exactly 
cylindrical cells and scarcely any trace of constrictions between them. 
In the thickness of its trichomes it most nearly approaches А. hyalina, 
Schmidle, but is very different in other characters and in its habit. 
393. ANABENA sPHLERICA, Born. & Flah. in Ann. Sci. Nat. T sér., Bot. 
vii. (1888) p. 228. 
Forma tenuis: crass. trich. 4-5 и; crass. heterocyst. 55 ш; long. spor. 
11-14 р; lat. spor. 10 p. 
Nyasa.—Among Utricularia, Domira Bay (19 June, 1904 ; no. 579). 
The filaments are rigid and straight, and except for being a trifle thinner 
agree in every particular with the description of A. splurrica. It is similar in 
size to А. baltica, J. Schmidt, but the trichomes of the latter are strongly 
flexuose and circinate, and the spores are relatively larger. 
294. АМАВЖХА sp. ad A. басат, J. Schmidt, accedens ; trichomatibus 
valde flexuoso-circinatis ; cellulis globosis, diam. 3-3°5 ш; sporis non vidis. 
Nyasa.—In plankton, Anchorage Bay (13 June, 1904 ; no. 9). 
Genus NODULARIA, Mertens. 
295. NoDULARIA sPHJEROCARPA, Born. & Flah. 1. с. (1888) p. 245. 
Crass. trich. 6 д. 
Tanganyika.—On surface of swamp, Toa (10 Jan. 1905 ; no. 208). 
296. NODULARIA TENUIS, sp. n. 
N. filis tenuibus, brevibus et rigidis, utroque fine paullo attenuatis et 
cellula acute conica terminatis ; vagina tenerrima, hyalina et difluente, vix 
eonspicua ; cellulis ante divisionem diametro æquilobis, rotundo-quadratis ; 
heterocystis late ellipsoideis ; sporis . . .? | 
Crass. trich. 3—3°8 ш; crass. heterocyst. 55-6 ш ; long. heterocyst. 7 p. 
