The Freshwater Algae of Africa. 537 



Samples 29 and 33 (on Cladophora glomerata), 39 (on Zygnema 

 spirale, n. sp.), 53 and 54 (on Oedogonium spp.). 



(2) CHAETOSPHAERIDIACEAE. 

 Genus CHAETOSPHAERLDIUM Klebahn. 



1. Chaetosphaeridium globosum (Nordst.), Klebahn, Pringsh. Jahrb., 

 xxv, LS93, p. 306, Tab. XIV, figs. 5-10. (Syn. : Herposteiron globosa, 

 Nordst. ; Aphanochaete globosa, Wolle). 



Samples 39 (rare, epiphytic on Zygnema spirale, n. sp.), 53 (very 

 rare, on Oedogonium spp.). 



(4) COLEOCHAETACEA E. 



Genus COLEOCHAETE Brebisson. 



1. Coleochaete scutata, Brebisson, Ann. Sci. nat., ser. 3, Bot., i, 1844, 

 p. 29, PI. II, figs. 1-7. 



Samples 2'. 1 , 29a, and 30a (on Myriophyllum) , 53 (on Oedogonium 

 sp.). 



(5) CH AETOPELTIDAC EA E. 



Genus CHAETOPELTIS Berthold. 



1. Chaetopeltis sp. (?). (Pig. 19.) 



Sample 44 (on DichothrLr spiralis, n. sp.). 



I have been at a loss as to the systematic position of this form, but 

 think the reference to the Ohaetopeltidaceae may prove correct, 

 although in the present material (even when stained) it has been 

 impossible t<> recognise any of the characteristic hairs.* The Alga 

 occurred as roughly circular discs or somewhat elongated convex 

 cushions (typical dimensions: 120 x 90, 200 X 108, 230 X 96 p), 

 generally attached to the abundant Dichothrix, often at the points of 

 branching of the latter (Pig. 19). In some cases the shape was a 

 rather irregular one, with a number of projecting lobes. The com- 



* According 1" Berthold (Ueb. d. Verzw. einig. Suesswasseralg., loc. cit., 

 p. 217), the formation of these hairs is very variable in Chaetopeltis orbicularis, 

 Berth., old plants being sometimes devoid of them tor a considerable length 



of time. 



