Nr. 1] SUBAÉRIAL ALGAE FROM SOUTH AFRICA at 
matophore has often distinetly receded from the membrane, which 
is no doubt only to be considered as phenomena due to con- 
traction during the gradual exsiccation. The edge of the chro- 
matophore is even, or it may sometimes be more or less emarginate 
and irregularly denticulate, and at times I have seen specimens 
with almost netieularly latticed chromatophore. Å pyrenoid is want- 
ing. The nucleus is situated in the centre of the cell. The membrane is 
always very tbin and colourless, without a mucous envelope, gene- 
rally glabrous, but sometimes distinetly crenulate. T his erenulation 
may be local, only limited to certain parts of the membrane, or the 
latter may be erenulate (all over the surface. Small as well as large 
cells may have crenulate membranes. The size of the cells is rather 
varying, from diminutive to 22 u in diameter. The average size, 
ihough, is 8—16 u. The number of the zoospores is very varying 
according to the size of the mother cell. Their shape is ovoid or 
ellipsoid, 2—3 u in length, and a lateral chromatophore may some- 
times be pointed out, filling only about half of the inner part of the 
zoospore (pl.I, fig.51). The zoospores are liberated by the rupture of 
the mother membrane. In samples of this species vacuous chapped 
membranes frequently oceur (pl. I. fig. 46, 47, 49, 50, 51), which 
must be considered as emptied zoosporangies. Thus, the membrane 
does not gelatinize. Besides in free state, I have also met with this 
species as lichen-gonidia. 
The species occurs in the following samples: 25, 28, 60, 75, 78, 
85, 158, 237, 238, 245, 253, 260, 340, 359, 364, 365, 370, 373, 375, 380, 
383, 390, 400, 401, 402, 403. 
— Chlorella vulgaris Brvyerinck, Bot. Ztg. 48 (1890) p. 758. IPI. 
II, Fig. 90—1041. 
This species occurs sporadically around Durban, but I have not 
found it in any of the samples from Saldanha Bay. It thus seems 
to be rather rare in the territory investigated, at least far more rare 
than e. g. in northern Europe, where the species is, indeed, one of 
the most frequent algae. The cells measure 7—9 u in diameter 
when full-grown; only oceasionally they are larger, up to 12 u. 
By the growth of the autospores the membrane of the mother cell 
gets dilated, however, and it may then attain larger dimensions. 
The characteristic feature of the species is the cup-shaped or 
spherieal, parietal chromatophore, which lines the inner cell-wall 
and fills it entirely, only leaving a larger or smaller, nearly cir- 
cular or ovate, colourless opening; a pyrenoid is not distinet. The 
cell-wall is rather thick and solid, without a mucous envelope, gla- 
brous, or sometimes finely crenulate all over the surface, or only 
partly so. The autospores are globose and develop in å small num- 
ber (2—38) in the mother cell, and are detached by the bursting of the 
old membrane. Their diameter is 4—5 pm and when still encom- 
