10 HENRIK PRINTZ [1920 



The characteristic feature of 'this species is above all its distinotly 

 and coarsely verrucous membrane. There is no usual crenulation of 

 the membrane, but it is more or leiss densely beset with rather 

 coarse, subobtuse warts. It is frequently seen that one side of Ihe 

 colonies may be more or less smooth, e. g. pi. I, fig. 18, 21, 22, 25, 

 26. This is due to the faet that the colony on the smooth or less 

 verrucous side has been recentlj' detached from a larger colony. 

 The prominences thus grow out only from tbe free surfaces of the 

 cells. The cells are more or less globular, or by mutual compression 

 somewhat angular, generally with a diameter of 5,5 — 7 /<, some- 

 times, just before the division, up to 8 — 9 /t. Mostly colonies of 

 2 — 4 or 8 cells occur; larger colonies are more rare, as tbey are easiiy 

 detached. The membrane is rather thick, hyaline. The chromato- 

 phore is bell-shaped, parietal, and occupies the whole of the inner 

 wall. There is no pyrenoid. 



On account of its warty membrane, this species recalls 

 Hansgirg's Pleurococcus crenulatus (Prodrom. I, 1886, p. 133, 

 fig. 82), but differs from it in having a much more coarsely warLy 

 (not crenulate) membrane, and in the shape of the cells. P. 

 crenulatus Hansg. is hardly any real Protococcus at all; acoordinig 

 to De Wildeman it is akinetes of Hormiscia crenulata (ofr. 

 E. De Wildeman : Note sur l'Ulothrix crenulata KiJTZ. in 

 Gompte-rendu de la seance du 4. décembre 1887 de la Société 

 Royale de Botanique Belgique). 



The species seeins lo be rare, as I have only found it in two 

 samples (29o, 294) from trunks of trees in the wood above Bluff. 



Chlorococcum vitiosum nov. spec. [PI. I, Fig. 31 — 511. 



Cellulis globosis magnitudine multum variantibus, vulgo dia- 

 metro 8 — 16 jLi, rarius usque ad 22 ja, vel etiam usque ad pauca jk 

 diametro decrescentibus. Membrana tenui, hyalina, glabra, tegu- 

 mento mucoso nullo. Interdum cellulae et magnae et parvae mem- 

 brana plus minusve distincte crenulata occurrunt. Chromatophoro 

 viridi, parietali, fere hemigloboso et dimidlum fere parietem interio- 

 rem cellulae obtegente. Pyrenoidibus nullis. Nucleo centrali 

 singulo. Zoosporis numero vakle variabilibus usque ad numerosis- 

 simas in cellulis singulis ortis, membrana materna dirupta liberis. 

 Zoosporis ovatis, 2 — 3 u longis, chromatophoro unilaterrdi, parietali 

 instruclis. 



This species is one of tbe commonest aérophilous algae in the 

 samples collected. I have met with it in several of tbe samples from 

 the environs of Durban as well as from Saldanha Bay. From other 

 species of the genus Chlorococcum this especially differs in its 

 chromatophore, which is hemispherical, covering only about one 

 half of tbe inner cell-wall. whereby the other half of the cell gets 

 colourless. In the material I have had for examination, the chro- 



