The Freshwater Algae of Africa. 



(501 



recognised. The posterior end is usually bluntly rounded. The 

 periplast is provided with a very fine striation, which often runs 

 almost transversely (cf. Fig. 42, B). The chloroplasts appear to be 



Fig. 42. — A. Euglena oxyuris, Schmarda. B. Euglena,n. sp. (?). C. Phacus 

 brevicaudata (Klebs) Lemmerm. (?). All tigs, x 700. 



numerous and disc-shaped, and there are a large number of oval 

 paramy Ion-grains. The rather elongated nucleus is generally to be 

 found near the middle of the cell, although sometimes (Fig. 42, B) it 

 lies nearer the front end. The dimensions of two typical specimens 

 were 132 x 39 //, and 153 x 33 //,. 



