118 MR. С. S. WEST ON THE FRESHWATER ALGAE 
81. Cosmartum GLOBOSUM, Buln. in Hedwigia, ii. (1861) p. 52, t. 9. fig. 8. 
Var. Мош, W. & G. S. West, т Trans. Linn. Soc. ser. 2, Bot. v. (1896) 
p. 252, t. 15. fig. 17.—C. globosum, Wolle, Desm. U.S. (1884) p. 60, t. 49. 
figs. 15-17. 
Forma major: long. 44-19 р; lat. 37-39 ш; lat. isthm. 35-37 p. (РІ. 4. 
fig. 10.) 
Victoria Nyanza.—In swampy pools, Bukoba (20 Apr. 1905; поз. 251 
and 618). 
Tanganyika.—In swamp close to shore, Kituta (23 Aug. 1904 ; nos. 72 
and 73. Also 26 Aug. 1904 ; по. 80). | 
This Cosmarium occurred in some abundance, and is characterized by the 
slightness of its constriction. In outline the African specimens agreed 
exactly with the figures given by Wolle, but they were of decidedly larger 
dimensions. 
There is one pyrenoid in each semicell, from which radiate a number of 
vertically-disposed divisions of the chloroplast. 
The specimens very closely resemble a Desmid described by Schmidle from 
Zanzibar as Dysphinctium subellipticum (vide Engl. Bot. Jahrb. xxvi. (1898) 
р. 21, t. 1. fig. 15), but there was no large series of punctulations on each side 
of the isthmus. 
82. CosMARIUM SUBCONSTRICTUM, Schmidle, in Engl. Bot. Jahrb. xxx. (1901) 
р. 66, t. 2. fig. 4. 
Long. 27-30 ш; lat. 26-28 ш ; lat. isthm. 17-20 ш; crass. 17-19 д. 
Victoria Nyanza.—In swampy pools, Bukoba (20 Apr. 1905; nos. 251 
and 618). 
This species was fairly abundant, and seems well characterized by its 
shallow constriction and by the two pyrenoids in each semicell. 
83. Cosmartum REGNESI, Reinsch, in Abh. Naturh. Ges, Nürnb. iii. (1866) 
р. 112, t. 7. fig. 8 ; G. 5. West, in Journ. Linn. Soc., Bot. xxvii. (1899) p. 387, 
t. 10. figs. 10-21. 
Tanganyika.—In swamp, Kituta (23 Aug. 1904 ; no. 12). 
84. CoswARIUM PLANUM, И”. $ G. S. West, in Trans. Linn. Soc. ser. 2, Bot. 
v. (1895) p. 59, t. 8. fig. 9. 
Long. 29 ш; lat. 18 р; lat. isthm. 6 p. 
Nyasa.—In shore pools, Nkata Bay (23 June, 1904 ; по. 22). 
85. COSMARIUM MINIMUM, W. $ G. S. West, l.c. p. 58, t. 8. fig. 10. 
Several slightly different forms. 
Tanganyika.—In swamp, Kituta (23 Aug. 1904 ; no. 12). 
