Fresh-water Alga. 69 



Class BACILLARIE^E. 

 Order CENTRICiE. 



Family COSCINODISCACEiE. 



39. Cyclotella Meneghiniana, Kiitz. 

 Karoo. In spring at Gansfontein ; 2.12.08. 



Little Namaqualand. In dam at Henkriesfontein ; 14.1.09. 



40. Cyclotella Kilt zingi ana, Chauvin. 



Little Namaqualand. Among floating algae and Cham sp., 

 Dabainoris ; 11.1.09. 



Great Namaqualand. In cattle-trough at Griindoorn ; 4.2.09. 



Order PENNAT.E. 



Family TABELLARIACE/E. 



41. Denticula tenuis, Kiitz. 



Upper (or Composite) Kegion. Holle Eiver ; 10.12.08. 

 Little Namaqualand. In dam at Pella ; 8.1.09. Among various 

 algae at Dabainoris ; 11.1.09. In dam at Kamiebies ; 24.12.08, 

 In some of the above localities this species was very abundant. 



Family FRAGILARIACEtE. 



42. Fragilaria virescens, Ralfs, var. cxigua, Grun. (Van Heurck, 

 Synops. Diat. Belg. c. 44, f. 3). 



Angola. In small stream in Cazengo District. 



43. Synedra Acus, (Kiitz.) Grun. 



Little Namaqualand. In water-pit at Eenriet ; 15.1.09. Var. 

 delicatissima, (W. Sm.) Grun. 



Little Namaqualand. In dam at Pella ; 8.1.09. 



44. Synedra Ulna, (Nitzsch) Ehrenb. 

 Angola. In stream in Cazengo District. 



Karoo. In sulphureous spring at Gansfontein ; 2.12.08. 



Upper (or Composite) Region. Holle River ; 10.12.08. 



Little Namaqualand. In running water at Henkriesfontein ; 

 14.1.09. In dam at Kamiebies; 24.12.08. 



Cape Region between Ceres and Karoopoort. Leeuwefontein ; 

 28.12.08. 



6 



