OF THE THIRD TANGANYIKA EXPEDITION. 123 
One other curious feature of C. lacunatum 13 the narrowness of the vertical 
view, which is 21 times longer than broad. 
Compare also with C. sublatum, Nordst. 
105. COSMARIUM PSEUDOBROOMEI, Wolle, Desm. U.S. (1884) p. 86, t. 51. 
figs. 36, 37 (fig. not good) ; W. В. Turner, in К. Sv. Vet.-Akad. Handl. xxv. 
(1893) n. 5, p. 66, t. 9. fig. 41; W. $ G. S. West, in Trans. Linn. Soc. ser. 2, 
Bot. vi. (1902) p. 170, t. 21. fig. 4. 
Nyasa.—In swamp, Kota Kota (20 June, 1904; по. 18). In swamp, 
Karonga (2 July, 1904 ; no. 34). 
Tanganyika.—In plankton, Lofu River (5 Oct. 1904 ; по. 123). 
Var. COMPRESSUM, var. п. (Pl. 7. fig. 11.) 
Var. cellulis paullo latioribus quam longioribus, angulis superioribus magis 
rotundatis. 
Long. 30 p ; lat. 35 p ; lat. isthm. 8 ш; crass. 18 р. 
Tanganyika.—Abundant in swamp, Kituta (23 Aug. 1904 ; по. 72). 
Since Wolle's somewhat crude account of C. Pseudobroomei in 1884, the 
species has been found in many parts of the world and is now very well 
known. 
А number of varieties have also been discovered, some of which appear to 
be well-marked and of constant character. The African variety most nearly 
approaches var. convexum, W. & ©. S. West (in Trans. Bot. Soc. Edinb., 
Nov. 1904, p. 21, t. 1. fig. 22), in the roundness of the upper angles of its 
semicells, but the general proportions and the basal angles are quite different. 
106. Cosmarium onEPERUM, W. & G. S. West, in Trans. Linn. Soc. ser. 2, 
Bot. v. (1895) p. 63, t. 7. fig. 11. 
Victoria Nyanza.—Among Ufricularia, near Entebbe (1 May, 1905 ; 
no. 620). 
This plant differs from typical C. Pseudobroomei in its open sinus and in 
its fewer and relatively smaller granules. In view, however, of the recently 
discovered varieties of С. Pseudobroomei, it would perhaps be better regarded 
as a variety of that species. 
107. CosMARIUM PsEUDAMCNUM, Wille, in Bih. К. Sv. Vet.- Akad. Handl. 
viii. (1884) по. 18, p. 18, t. 1. fig. 37.—C. inornatum, Joshua, in Journ. Linn. 
Soc., Bot. xxi. (1886) p. 648, t. 24. figs. 26, 2T. 
a. Forma paullo major: long. 59 ш; lat. 28 р; lat. isthm. 23 р. 
Tanganyika.—In swamp, Kituta (23 Aug. 1904 ; no. 72). 
$. Forma major et paullo longioribus: long. 71 ш; lat. 29 ш; lat. 
isthm. 24 д. 
Tanganyika.—In swamp, Kituta (26 Aug. 1904 ; no. 80). 
Many of the specimens of the latter form were considerably larger than 
any I have previously examined, and in some the granules were more evidently 
arranged in transverse than in longitudinal series. 
