Nr. 1] SUBAERIAL ALGAE FROM SOUTH AFRICA 15 



meitabolism, the real nature of which I have had no opportunity to 

 examine, however. With regard to the chromatophore, it is further 

 to be noliced that the oolourless incision as a iiile is situated iii 

 the side of the cell opposite the membrane wart. 



The nucleus is comparatively large and nearly centrally located, 

 but it is not visible except after treatment with the special tesits and 

 colouring matter. By succedaneous divisions of the contents of the 

 cells a varying number of zoospores arise. Whether these oell- 

 diivisions are always pierfectly regular, I diare noit decide witli 

 absolute certainty; however, the first division in all the rather 

 numerous specimens I have obser\'ed, seems to be orienlated nearly 

 perpendiculai'ly on the membrane-inspissation (vide fig. 119, pi. 

 II), The zoospores are nearly ovoid, + 3 ^ long, The materiail I 

 have had at my disposal has been loo badly preserved to be suitable 

 for investigations on the cilies. The zoospores escape singly through 

 an opening in the mother membrane. 



This alga occurs sparsely in some of the siunples from the 

 environs of Durban, frequentlv togelher with Pleurastnim con- 

 stipatum (16, 52, 85, 302). 



Acanthococcus granulatus Reinsch var. aerophilus nov. var. 

 [PI. II, Fig. 79—89]. 



Differt membrand crassiuscula, aculeis imparibus, crassis, 

 cuneatis, irregiilariter dispositis, iiistriicta. Cellula diametro 3 — 30 a, 

 vulgo 10—20 1,1 lata. 



This alga I have found to be conimon in quite a number of 

 samples from the environs of Durban, but I have not observed it in 

 a single sample from Saldanha Bay. It is very varying as to the 

 size of the cells, the thickness of the membrane, as well as in the 

 shape and distribution of the prominences. However, the specimens 

 observed by me hardly comprise more than a single species, but with 

 a considerable range of variation. The decided aérophilous algae 

 are hardly identical with the species living in freshwater, but as the 

 sipecimens found by me, as to the shape of their cells, muoh recall 

 A. granulatus, I have founded the alga in question as a variety 

 of this one. 



The cells are spherical, at times somewhat irregular, usually 

 10—20 IA, rarely reaching a size of about 30 ^i in dii-an:Leter, enclosed 

 by a homogenous, colourless membrane, up to 4 ^i thiek. The pro- 

 jections are usually coarse, rather short and thick, with bluntish 

 tops; specimens with more pointed projections occur, however; at 

 times they are also shorter and more stubby, to almost hemispheri- 

 cal. The projections are rather distant, irregularly distributed on the 

 surface of the cell, and rather varying on one and the same oell 

 both as to size and shape. Sometimes the projections or warts are 

 seen to be somewhat reduced on one side, which, no doubt, is due 



