Fresh-water Alga. 67 



This species was originally described from Angola in 1897. 



27. Phormidium foveolarum, (Mont.) Gomont. 



Angola. Attached to the sides of water-conduit at the cable-station, 

 Mossamedes. 



28. Phormidium laminosum, (Ag.) Gomont. 

 Crass, trich. 1-4 fi. 



Upper (or Composite) Eegion. On drying mud, Holle Eiver ; 

 10.12.08 



Little Namaqualand. In dam at Pella ; 8.1.09. 



29. Phormidium fragile, (Menegh.) Gomont, forma tenuis, W. 

 & G. S. West, in Eeport on Sci. Investig. British Antarctic Expedi- 

 tion 1907-9, vol. L, part vii., 1911, p. 291, t. 25, f. 76. 



Crass, trich. - 9-l /.<. 



Angola. In slightly saline marsh south of the mouth of Eiver 

 Bero, Mossamedes. 



Upper (or Composite) Eegion. On drying mud in river-bed, 

 Holle Eiver; 10.12.08. 



30. Phormidium molle, (Kivtz.) Gomont. 

 Little Namaqualand. In dam at Pella; 8.1.09. 



31. Phormidium tcnue, (Menegh.) Gomont. 



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

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

 Henkriesfontein ; 14.1.09. Floating in pool at Aggenys; 6.1.09. 



32. Phormidium sp. 



This alga stands near to Phormidium Corium, (Ag.) Gomont, but 

 differs in several essential points. The trichomes are pale 

 aeruginous, 2-5-3 - 8 fx in thickness, and slightly attenuated towards 

 the extremities. Cell-walls distinct, and here and there apparently 

 thickened in a somewhat irregular manner. The material was 

 insufficient for complete investigation, and for the present I hesitate 

 to say anything more definite concerning its specific identity. 



Angola. In a saline marsh south of the mouth of the Eiver Bero 

 Mossamedes. 



33. Lyngbya major, Menegh. 

 Crass, fil. 22-25^; trich. 17'5-18 A< . 



Little Namaqualand. In spring at Henkriesfontein ; 14.1.09. 



34. Sjjmploca thermalis, (Kiitz.) Grun. 



Great Namaqualand. Forming, along with Phormidium angustis- 

 simum, a short column from the base of a pool in a sulphureous 

 spring at Warmbad. Temp, of water 35° C. 



