OF THE THIRD TANGANYIKA EXPEDITION, 111 
46. PLEUROTÆNIUM ELATUM, (W. B. Turn.) Borge, in Bih. К. Sv. Vet.- 
Akad. Handl. xxiv. (1899) Afd. 3, по. 12, p. 16.—Docidium elatum, W. В. 
Turn. in K. Sv. Vet.- Akad. Handl. xxv. (1893) no. 5, p. 27, t. 2. fig. 16. 
Docidium robustum, W. B. Turn. l. с. р. 27, t. 2. fig. 8. 
Var. CONJUNCTUM, (W. В. Turn.) W. у б. S. West, in Trans. Linn. Soe., 
ser. 2, Bot. vi. (1902) p. 144.—Docidium conjunctum, W. B. Turn. l.c. 
р. 32, t. 4. fig. 6. 
Long. 530-561 ш; lat. ad bas. semicell. 45-48 д; lat. apic. 40-42 y. 
Tanganyika.—In plankton, Lofu River (5 Oct. 1904; nos. 123 and 124). 
The individuals observed were slightly larger than Turner's measurements 
of P. elatum var. conjunctum, but not so large as the forma duplo-major 
described from Ceylon. The lateral margins of the semicells were slightly 
undulate from base to apex, and each apex possessed 26-27 tuberculi. The 
individuals remained attached by their apices, and filaments of 15 cells were 
observed. 
47. PLEUROTANICM CALDENSE, Nordst., in Ofvers. К. Vet.-Akad. Fórh. 
(1877) no. 3, p. 17, t. 2. fig. 2. 
Forma AFRICANA. (РІ. 6. fig. 1.) 
Forma cellulis longioribus, leviter attenuatis apices versus, tuberculis 
apicalibus 18 (9—10 visis). 
Long. 670 р; lat. ad bas. semicell. 34 р ; lat. apic. 25 р. 
Nyasa.—In swamp, Karonga (2 July, 1904 ; по. 34). 
The African form differs principally from the Brazilian one in the distinct 
attenuation of the apical part of the semicells. 
48. PLEUROTÆNIUM EHRENBERGII, (Breb.) De Bary, Conj. (1858) р. 75 ; 
W. & G. S. West, Brit. Desm. i. (1904) p. 205, t. 29. figs. 9-11.— Docidium 
Ehrenbergii, Эте. 
Nyasa.—In swamp, Karonga (2 July, 1904 ; nos. 33 and 34). 
Victoria Nyanza.—In swampy pools near Bukoba (20 Apr. 1905 ; nos. 251 
and 618). 
Tanganyika.—In swamp, Kituta (23 Aug. 1904; no. 72. Also 26 Aug. 
1904; no. 80). 
49. PLEUROTÆNIUM TRABECULA, (hrenb.) Ndg. Gatt. einz. Alg. (1849) 
р. 104, t. 6. fig. А; W. 4 G. S. West, l.e. p. 209, t. 30. figs. 11-13, 
Victoria Nyanza.—In swampy pool near Bukoba (20 Apr. 1905 ; no. 251). 
50. PLEUROTÆNIUM MAXIMUM, (Reinsch) Lund. in Nov. Act. Reg. Soc. Sci. 
Upsal. ser. 3, viii. (1871) p. 89; И’. & G. S. West, l. c.ip. 213, t. 31. figs. 1, 2.— 
Docidium maximum, /teinsch. 
Long. 720 р; lat. ad bas. semicell. 40 p, ad apic. 28 р. 
Tanganyika.—In swamp, Kituta (23 Aug. 1904; no. 72). 
