18 HENRIK PRINTZ [1920 
the cells get å nearly ovoid shape. The chromatophore is a pallid 
green, parietal slab, and does mot line more than one half of the 
membrane. Because of this, the poles of the cells are commonly 
colourless, or the chromatophore is lateral, and fills one half of the 
cell only, by which the other half gets colourless. In the 
cells are often to be found small refractive grains. Å pyrenoid! is 
wanting. 
In the course of time have been referred to Stichococcus bacil- 
laris å great number of various forms, many of which are certainly 
quite different species. If the drawings given by the different 
authors are compared, great disagreements will be observed both 
in the shape, size, and inner structure of the cells. Further, some 
authors record the species to have a pyrenoid, others åa pyrenoid to 
be wanting. In my opinion, however, the presence or absence of a 
pyrenoid is no particularly important systematic character, as 
among algae of undoubtedly near relationship, one species may 
have, the other one may be destitute of a pyrenoid. To make a 
distinction between two genera solely on such a character as the 
absence or presence of pyrenoids, as e. g. to establish the genus 
Palmellococcus ineluding the species of Ghlorella, wanting the pyre- 
noid, therefore may not be quite well-founded in systematical re- 
spects. Within one and the same species, however, this is a constant 
character. It is also dubious what systematical importance should 
be assigned to a character, as whether the cells of Stichococeus 
coher in rows or disintegrate immediately after the cell-divisions. 
This character, at any rate to å certain extent, may be dependent on 
the nature of the habitat, especially perhaps on the conditions of 
humidity, and is in some degree, at least, not without influence on 
the shape of the cell-ends. The specimens found by me from South 
Africa, agree perfectly with the description and figures of the species 
St. minor, fig. 66, given by HEERING in PAScCHERS Algenflora; 
especially characteristic are the oblique or somewhat curved cells, 
with the broadly rounded ends. 
Pleurastrum constipatum 10v. spec. [P1. IIT, Fig. 124—155]1. 
Thallo ex struibus cellularum parencymaticarum irregulariter 
formatis, 1-plures cellularum series crassis, numero variabilium 
usque ad amplius centum cellularum constante. Gellulis singulis 
et magnitudine et forma multum variis. Cellulis brevi post 
divisionem ad 3,5 u parvis, adultis et majoribus ante divisio- 
nem usque ad 9 um magnis. Cellulis polygeneis, fere isodia- 
metricis parietibus pro ratione crasis instructis. In cellulis nucleis 
singulis. Chromatophoro campanulato totum parietem interiorem 
obtegente, nullas partes vacuas achroas relinquente. Pyrenoidibus 
nullis. Acinetis propagationis cellulis singulis rotundatis et dis- 
solutis ortis. Zoosporis parvis, 1,5—1,8 u longis in sporangiis, neque 
