71 
monostromatie frond, more frequently however at the border, where the cells are 
therefore a little smaller and closer together. The intensive marginal growth 
results in the margin becoming much undulated. In fig. 9 C, which was drawn 
after a dried specimen, the cells are seen to be arranged in groups of two or four 
or a little more, rather distant from each other. 
As said above, the reproduction has hitherto been unknown in this species, 
and I have also searched in vain for any indication of a fruclification in several 
fully developed specimens. In other cases, however, I succeeded in finding a for- 
mation of spores corresponding lo that in Erythrotrichia; even in very small spec- 
imens it could be observed. Thus in fig. 9 B several cells are divided by an in- 
elined curved wall into a roundish cell filled with protoplasmie contents, the 
spore-mother cell, and a crescent-shaped sterile cell. The spore-mother cells are 
scattered without order over the whole frond; even marginal cells may produce 
them (fig. 9 B, at the summit). In fig. 10 is shown a small fragment of another, 
larger plant where most of the cells have produced spores. As I have only exa- 
mined the plant in preserved condition I cannot give any information of the be- 
‚haviour of the sterile cell on the escape of the spore. 
The described fructification along with the peculiar develop- 4 
ment of the frond justify the establishment of this plant as the 3 2 2 
representative of a new genus. On account of the resemblance 6 © 1e 
in appearance to the genus Porphyra I have named it Porphyropsis; 09e 
& 
a diagnosis is given above. 
Only found in the eastern Kattegat in 20 to 25,5 meters depth, Fig. 10. 
epiphytic on various Alge. The largest specimens, 5 mm. high, AC en 
with much undulated margin, were met with at the end of July; rangia. 630:1. 
young plants were collected in May and July. 
Localities. Ke: Fladen, ZF, on stalks of Laminaria digilata, on Dilsea edulis and Rhodymenia 
palmata a.o.; Groves Flak, VZ, on Desmarestia aculeata; Lille Middelgrund, IK, on Odonthalia dentata. 
Erythrocladia gen. nov. 
Thallus horizontaliter expansus, e filis ramosis, aliis algis adfixis, radiatim 
egredientibus, initio inter se discretis, dein in discum tenuem unistratosum confluen- 
tibus, constans. Crescentia filorum apicalis. Sporangia eodem modo ac in genere 
Erythrotrichia in cellulis intercalaribus vel rarius terminalibus gignuntur. Generatio 
sexualis adhuc ignota!. 
1 Barrers has in 1896 (Journ. of Botany Vol. 34) established a genus Colaconema, characterized 
by branched filaments living in the cell-walls of various Algæ and by monosporangia “formed from 
portions cither of the terminal cells of the principal axes, or of short swollen 1- or few-celled lateral 
branches, or even from a portion ofa cell in the continuity of the filament. The undifferentiated por- 
tions of the cells forming cup-like bases for the sporangia’. This genus was later placed by Barrens 
(Journ. of Bot. Vol. 40, 1902, Supplement p. 57) near to the genus Acrochætium (Chantransia) and one 
species was removed to this genus. The indicated mode of formation of the monosporangia suggests 
however that the genus may include forms belonging to the Erythrotrichieæ, and the sporangia arising 
