Nr. 1] SUBAÉRIAL ALGAE FROM SOUTH AFRICA 17 



The speciniens from these cMfferent localities evince in their broad 

 features a close congruity. The cells are joined in rather long and 

 usually straight filaments, consisting of up to 100 cells or more. 

 Ihe cells are on an average 8—9 a broad, and nearly equally long 

 — up to twice as long as broad,' rarely shorter than broad. The 

 filaments are equally broad, at times slightly constricted at the 

 dissepiments. The chromalophore is entire at the edges, and the 

 comparatively large pyrenoid rather easily discerned. I have 

 observed some few speciniens forming zoospores. These arise singly 

 in each oell, as desci-ibed and delineated by WiLLEtOm Udviklingen 

 af Ulothrix flaccida Kutz. (Svensk Bot. Tidskrift 1912), and I have 

 nolhing to add to.what is already known from these investigations. 



Besides this one I have found a somewhat different form: ceilulis 

 passim tumidis Gay, Alg. Xeri. (1891) p. 97, pi. XI, fig. 106. 



In pi. VI, fig. 233 — 243 I have drawn a series of speciniens of 

 this one. Here the filaments are composed of very few cells only, 

 usually 2 — 4, rarely wLth up to 8 — 12 cells in each filament. Very 

 frequently are aiso to be found single cells — alcinetes — of an 

 ovoid-globose shape. At the fracture the oells are ver}' quickly 

 inflated, but often there is to be found on these akinetes small 

 inspissations in the membranes on each side, as the membrane will 

 also be seen to be flattened. These akinetes divide by a cross-wall, 

 and grow directly into new filaments. The breadth of the oells varies 

 belween 6 — 10 /t, on an average 7 — 8 u, and the length is comnionly 

 equal to the breadth, but varies between one half to nearly twice the 

 breadth. 



I sujipose this latter form is identical with Stichococcus dissectus 

 Gav, 1. c. p. 96— 100 (Hormidium r/issecf nm (Gav) Chodat). Cultures 

 show that the degree of dissociation of the cells is dependent on the 

 nalural conditions of the habitat, and this character is therefore 

 without any systematical importance whatever. 



CoUected on decayed wood above Bluff, near the Signal station 

 at the entrance of the harbour of Durban, Oct. 28tli (no. 24). 



Stichococcus bacillaris Nageli f. minor (Nageli) sec. Chodat, 

 Monogr. d'Algues en Culture Pure p. 155 (Matériaux pour la Flore 

 Cry]itogamique Suisse, Vol. IV. Fase. 2, 1913); Heering, Ulothrica- 

 les, etc. in Pascher, Siisswasser-Fl. H. VI, 1914, p. 52, Fig. 66. 



Under this name I class a small alga I have found in some 

 samples of bark and decayed wood from Bluff (Durban), and at 

 Ostenwald, Sa'danha Bay (nos. 145, 340, 343). The cells are always 

 single, small, usually 2,3 — 3,2 « broad, and 5 — 8 «, long. Their shape 

 is somewhat varying, almos-t cylindric and straight, with obtuse 

 ends or slightly curved and oblique, sometimes more elliptic, 

 broadest about the middle. It also happens that one end of the oell 

 may be more narrow and pointed than the other one, by which 



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