The Freshwater Algae of Africa. 



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Fig. I"). Spfcaeroplea africana, n. sp. J and J?. Parts of two "cells" 

 showing the varied disposition of the contents: eh. Chloroplasts ; 

 n. Nucleus; p. Pyi-enoid ; the nuclei are shown black, the chloro- 

 plasts shaded, f '. Small part of a filament, to show the customary 

 constriction at the septa; at the lower end a part of an oogonium, 

 with a number of oospores, is seen. I>. Single septum, seen from the 

 surface, shofving the ingrowing finger-like processes. E. Septum in 

 optical section. /■'. [mperfect septum. G. Early stage in septum- 

 formation. H. Oblique view of septum, showing its structure and 

 the apparent continuity of the protoplasm through it. All figures 

 x 550, except Fig. C, which is x 130. 



