The Freshwater Algae of Africa. 599 



3. Nitzschia com/munis, Rabenh. : Van Heurck, op. cit., p. 184, 

 PL LXIX, fig. 32. 



Samples 5,12,26*31. 



4. Nitzschia palea, Euetz. ; Van Heurck, op. '-if., p. 183, PI. LXIX. 

 tigs. 22b, c. 



Samples 4, 5, 6, 25, 26, 27, 30a, 31, 32, 33, 36, 37, 41, 43. 

 Recorded by G. S. West from the Halle River, Calvinia Division, 

 and Little Namaqualand. 



5. Nitzschia gracilis, Hantzsch ; Van Heurck, op. cit., PL LXVIII, 

 % 11- 



Sample 26. 



Long., 72 /jl; lat., 42 /x. 



Section NITZSCHIELLA (Rabenh.), Getjnow. 



1. Nitzschia acicularis, Kuetz. ; Van Heurck, op. cit., p. 185, PL LXX, 

 fig. 6. 



Samples 4, 32. 



2. Nitzschia lorenziana, Grun.; Van Heurck, np. cit.. p. 185, PL 

 LXX, fig. 12. (Fig. 41, c.) 



Samples 4, 5, 6. 



Long., 117-138 /x ; lat., 5 5-6 /x. 



This is really a marine species, but Hustedt (Beitr. z. Algenfl. v. 

 Bremen, ii, Abh. Xat. Ver. Bremen, xix, 1908, p. 448) has found var. 

 auhtilis, Grun., in fresh water. It is possible that the Cape specimens 

 really belong to this variety. 



Genus HANTZSCHIA Grunow. 



1. Hantzschio aMphioxys (Ehrenb.), Grun.; Van Heurck, op. cit., 

 p. LiS, PI. LVI, ligs. 1. 2. 

 Samples 6, 26, 27, 43. 

 Recorded from Little ami Great Namaqualand by G. S. West. 



E. SURIRELLOIDEAE. 



Genus CYMATOPLEURA W. Smith. 



1. Cymatopleura solea (Breb.), YV. Sm.; Van Heurck, op. cit., p. 168, 

 PL LV, fig. 1. 

 Samples 25, 32, 

 Long.. 57-132 /x ; lat.. L8 30 /<. 



