500 KJELLMAN, THE ALGA) OF THE ARCTIC SEA. 
Habitat. This species is always sublitoral in the Arctic Sea, growing scattered 
on exposed coasts, in 4—5 fathoms, attached to other alge or stones. On the northern 
coast of Norway I have found it partly in the upper part of the sublitoral zone near 
low-water mark, partly at a considerable (10—15 fathoms) depth attached to stones, 
shells or muscles both in exposed and sheltered localities. It is often met with here 
floating free on the water in large quantities or washed ashore. Specimens with zoo- 
spores have been collected in August on the coast of Spitzbergen. 
Geogr. Distrib. This species has its maximum of frequency in the Norwegian 
Polar Sea. In the other parts of the Polar Sea it is scarce and little spread. The 
most northern place where it is known to occur is Fairhaven on the north-west coast 
of Spitzbergen Lat. N. 79°49’. 
Localities: The Norwegian Polar Sea: Nordlanden abundant; Finmarken at Maaso, 
Gjesver and Talvik, everywhere abundant and rather common. 
The Greenland Sea: the north-west coast of Spitzbergen, rare. 
The Murman Sea: the coast of Russian Lapland: the west coast of Novaya Zemlya: 
here only a couple of fragmentary specimens found washed ashore. 
The White Sea: probably common. 
Baffin Bay: the coast of Greenland according to specimens in the herbarium of 
the Copenhague Museum; the exact place of occurrence not stated. 
Monostroma crispatum nob. 
M. fronde callo radicali adnato, membranacea, obovata, obscure viridi nigrescente, margine lacerato et 
crispo, inferne 170, superne 50 w. crassa; parte monostromatica e cellulis in sectione frondis transversa lumina 
qvadrangularia 35 uw. alta, 15—35 w. lata prabentibus contexta. Tab. 28, fig. 11—13. 
Description. This species belongs to the same section of the genus Monostroma 
as M. fascum and M. Blyttii. I have found only three specimens, all of which agree most 
closely. The largest of them is figured in natural size (tab. 28, fig. 11). It is 4 cm. 
long and 1,5 cm. broad upwards where its transverse section is greatest. It is obovate 
in outline as the others. The margin is laciniate and very crisp, the colour is dark 
green, almost black green, becoming black in drying. Its attachment is a callus radi- 
calis that is large in proportion to the plant. The stipe is short, but distinct (fig. 11). 
The greater part of the frond is formed of club-shaped cells with heads that are almost 
square in transverse section. The heads occupy the one side of the frond, the shafts 
the other. Upwards the frond is monostromatic, composed of cells square in transverse 
section, whose breadth is as great as or less than their height. The corners of the 
cell-rooms are slightly rounded. The endochrome does not cover the whole wall. The 
outer wall is comparatively thin. The frond is 50 «. at the upper margin, the height 
of the cell-rooms here is 35 u., the breadth 15—35 wu. The frond is still more than 
150 «. thick at the middle. The cells as seen from the surface are 4—6-angular with 
thin partition-walls. 
