78 Annals of the South African, Museum. 



96. Tetra'edron trigonum, (Nag.) Hansg., var. isoscelum, G. S. 

 West, var. n. 



Var. minimum, cellulis cum lateribus binis elongatis subrectis vel 

 leviter concavis, latere tertio breviori et valde retuso ; angulis minute 

 spinulatis. 



Diam. min. (c. spin.) 6-10 yu, max. 13-18 /u. (Figs. 33, 34.) 

 Little Naraaqualand. Floating in dam at Rozynbosch ; 9.1.09. 



97. Scenedesmus obliquus, (Turp.) Kiitz. 

 Angola. In stream in Cazengo District. 



Karoo. In sulphureous spring, Gansfontein ; 2.12.08. 



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

 algae at Dabainoris (in great quantity) ; 11.1.09. In dam at 

 Kamiebies ; 24.12.08. In great abundance in dam at Easynboch ; 

 9.1.09. 



Cape Region between Ceres and Karoopoort. In sulphureous 

 spring at Leeuwefontein ; 28.12.08. 



98. Scenedesmus bijugaius, (Turp.) Kiitz. 



Karoo. In sulphureous spring at Pappekuil ; 2.12.08. In similar 

 spring at Gansfontein ; 2.12.08. 



Little Namaqualand. In dam at Henkriesfontein ; 14.1.09. 

 Among various algae at Dabainoris ; 11.1.09. 



Forma ad Sc. incrassatulum, Bohlin, accedens, sed cellulis sine 

 apiculis. 



Angola. In stream in Cazengo District. 



Little Namaqualand. In dam at Rasynbosch ; 9.1.09. 



99. Scenedesmus acutiformis, Schroder, var. brasilicnsis, (Bohlin) 

 W. & G. S. West. 



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



100. Scenedesmus denticulatus, Lagerh., var. linearis, Hansg. 

 Karoo. In sulphureous spring, Beukesfontein; 1.12.08. Temp. 



of water 27-25° C. In similar spring at Gansfontein ; 2.12.08. 



101. Scenedesmus quadricauda, (Turp.) Breb. 



Karoo. In sulphureous spring at Beukesfontein ; 1.12.08; and in 

 similar spring at Pappekuil ; 2.12.08. 



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



Little Namaqualand. Among other algae at Dabainoris ; 11.1.09. 

 In stagnant pool in river-bed at Aus (colouring the water green) ; 

 21.1.09. In water-pit at Eenriet; 16.1.09. 



102. Dactylococcus bicaudatus, A. Br. 

 Long. cell. 24 /< ; lat. 4*5 fi. 



Little Namaqualand. In dam at Rozynbosch; 9.1.09. 



