Confrihntions to Our Knowledge of the Freshwater Algae of Africa. 69 
There are not many epiphytic species of Calothrix possessing the small 
dimensions of C. gracilis, and these are all distinguished by the termination 
of the trichome in a hair. C. epiphytica, W. & G. S. West, also differs in the 
thicker sheath, whilst C. scytonemicola, Tilden, is stated to have indistinct 
sheaths and usually two basal heterocysts. 
(Note. — Indeterminable material of this genus was also present in 
samples 81, 85 (0. adscendens (Naeg.), Born, et Flah. ?), 329, 335, 345.) 
IV. FLORIDEAE. 
(1) HELMmTHOCLADIACEAE. 
Genus CHANTRANSIA Fries. 
1. Chantransia chalyhea, Fries; Kuetzing, Spec. Alg., 1849, p. 429 ; Tab. 
Phycol., V, t. 41. 
Sample 33 (not uncommon). 
It has been established that this is actually a stage in the development 
of Batracliospermnm, but in the somewhat unusual habitat development to 
the adult form is not likely. 
V, PLAGELLATA. 
EUGLENINAE. 
(1) EUGLENACEAE. 
Genus EUGLENA Ehrenb. 
1. Euglena spirogyra, Ehrenb. ; Lemmermann, in Pascher, Suesswasserfl. 
Deutschlands, etc.. Heft 2, 1913, p. 131, fig. 208. (Fig. 29, A.) 
Sample 19 (common), 29 (very rare). 
The majority of the individuals possessed the straight body and straight 
posterior spine shown in Fig. 29, A, but occasionally the body had a slight 
spiral twist or the spine was bent to one side. The spirally arranged rows 
of granules on the periplast were very obvious, but appeared all to be of 
the same size, whereas the type is described as usually having two rows 
of smaller granules between each pair of larger ones. These granules are 
so numerous that they give the outline of the Euglena, as seen in optical 
section, a faintly crenate appearance. The angle made by the rows of 
granules with the main axis of the body varies somewhat, the rows 
