14 HENRIK PRINTZ [1920 
cedanee ortis, quae solitarie per porum membrance maternae 
itberantur. 
Myrmecia globosa nov. spec. [PI. II, Fig. 105—1231. 
Cellulis subrotunde-ovalibus libere et solitarie viventibus et 
adultis vulgo 16—19 u. Membrana achroa, crassiuscula, vulgo fere 
2 u crassa et latere uno in verrucam humilem, latam incrassata. 
Chromatophoro campanulato, parietali, totum parietem interiorem 
obtegente vel interdum uno latere, vulgo membranae incrassatae 
opposito, inciso. Pyrenoidibus nullis. Nucleo pro ratione magno, 
centrali. Propagatio zoosporis contentu cellulae maternae diviso 
succedanee ortis, zoosporis elongate-ovatis, 3—5,5 u longis et 
stigmate distincte instructis. Per porum membranac maternae 
solitarie liberantur. Alga aéris in cortice arborum crescens. 
This alga much recalls Kentrosphaera in the shape of the cells. 
This likeness is only seeming, however, and is mainly due to the 
external habitus of the cells, with a thick wall and a blunt, conical 
or papilliform excrescence. In the inner structure Myrmecia globosa 
differs distinctly from Kentrosphaera, thuswise in its chromato- 
phore, which is a parietal cup, lining nearly the whole of the 
cell-wall, while in Kentrosphaera the chromatophore is radiate, 
formed by numerous parietal slabs or ribbon-shaped rays. To the 
structure of the chromatophore there must be attached great 
importance in a case like this. Of other differences from 
Kentrosphaera must further be noticed the absence ofa pyrenoid, the 
smaller number of zoospores, formed by succedaneous divi- 
sions. In Kentrosphaera the divisions are simultaneous ina 
far greater number of zoospores. 
The inner structure of the cells shows, on the other hand, åa 
more close conformity to Chlorococcum, a genus which I consider 
as being one of the most nearly allied ones. The most essential 
difference from (Chlorococcum is the thick membrane, with åa 
unilateral projection, and the absence of a pynenoid, in so far as this 
last feature is to be considered as being of any systematical value. 
As the inspissation of the membrane of Myrmecia globosa is 
a unilateral exerescence only, one often has to displace, in a prepara- 
tion of this kind, the cells by means of a pressure on the cover glass 
in order to get sight of it. It is commonly comparatively lower 
and broader than usual in Kentrosphaera; in young cells it may 
even be conspicuous and of comparatively considerable dimiensions 
(e. g. fig. 114, pl. IT). The membrane is colourless and rather thick, 
its thickness being somewhat varying, usually + 2 u, and without 
any particularly pronounced stratification. Treated with chlor- 
iodide of zinc, it assumes a slightly violet tint. In the cup-shaped 
chromatophore there is no pyrenoid; on the other hand, there may 
be observed one or more dark spots, which probably are products of 
