en 
to me that some of the first were cystocarpic ones. As shown in fig. 170 the 
antheridial conceptacles occur in the same fronds as the cystocarpic ones. The 
latter were rather small in these specimens. 
The specimens growing on Corallina officinalis, collected north of Læsø (ZC!, 
7658a, fig. 171), are more vigorous than the specimens previously mentioned. The 
structure of the frond is the same, but the conceptacles reach greater dimensions. 
They may be hemispherical, 160—185 » in diameter, or they may be lower, fre- 
quently fusing together, when the conceptacles are densely placed. The ostiole was 
provided with small papillæ directed inwards in the conical space of the orifice. 
When seen 
from above, the 
ostiole appea- 
redsurrounded 
by a rosette ex- 
actly like that 
shown in fig. 
168 D. The re- 
mains of a col- 
umella were 
found in the 
case represen- 
ted in fig.171 À. 
The sporangia 
were always Fig. 171. 
tet : Melobesia Fosliei growing on Corallina officinalis from ZC!, north of Læsø A, vertical section 
etrasporic, 2 : 2 3 = 
of frond with two conceptacles, one hemispherical, the other depressed. B, vertical section 
44 —50 L long, of frond with antheridial conceptacle. C, vertical section of cystocarpic conceptacle. 
11-16, broad. A and C 260:1. B 420:1. 
— The antheridial conceptacles are slightly prominent; the spermatangia are pro- 
duced on the flat bottom of the conceptacle from small cup-shaped cells; they (or 
the spermatia) are linear-clavate, slightly curved, measuring 7 in length, about 
2 in their broader end. — The cystocarpic conceptacles have the same shape 
and size as the sporangial ones and are, as those, provided with short horizontal 
papillæ in the ostiole, principally in its under part. 
I have been much in doubt in determining the specimens referred to this 
species. Some of them, those from Bragerne, Skagerak, have been referred to M. 
Lejolisii by Foscie (Remarks, p. 106) and I have also been much inclined to con- 
sider them as a more or less reduced form of this species. However, I have judged 
it better to describe it as a new species, considering, besides other characters, 
especially the higher conceptacles of sporangia, the formation of the spermatia 
taking place in our species at the bottom of the conceptacle from short cells, while 
in M. Lejolisii they are produced at the end of long sterigmata, and the long curved 
spermatia, while those of M. Lejolisii are much shorter. The antheridial concep- 
32* 
