Contributions to Our Knowledge of the Freshwater Algae of Africa. 25 
ca. 10 laminis formata, pyrenoidibus niagnis 3-5 in serie axiali in quaque 
semicellula. Dimens., 351 x 57, 354 x 54, 378 x 55, 390 x 60, 400 x 55. 
405 X 60, 420 X 57 )a ; lat. apic, 6 /x. 
Sample 346 (common). 
This rather distinct species occurs in two forms, the one (f . fusiformis) 
showing a marked superficial resemblance to C. lihelhda, Focke, the other 
(f. genuina) somewhat resembling a stout specimen of G. pritchardianum 
Arch. ; the latter form is the more common. 
Fia. 7. — Closterium pseudolihelhda, F. E. Fritsch, n. sp. A and D, f. gemiina. 
B and C, f . fusiformis. E, F, G and H, apices of different specimens. I, 
disposition of the pnnctae on the membrane. A, B and D x 200; 0 x 320; 
remaining figures x 800. 
In f. genuina the ventral surface is either quite flat or very slightly 
convex; in rare cases it is very faintly concave. The ends are truncate 
(Fig. 7, F, H), or sometimes in young specimens rounded-truncate (Fig. 7, 
E, G) ; they are markedly recurved (Fig. 7, B), so that their appearance is 
very similar to that of the ends in C. pritchardianum. In f . fusiformis the 
recurved character is only very faintly indicated as a general rule (Fig. 7, B 
and G) — in fact in some individuals it is altogether indiscernible. A 
marked characteristic of the species lies in the fact that the membrane very 
soon takes on a yellowish or yellowish-broAvn tinge, and that the entire 
