KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. PPA 
later more numerous, sometimes so numerous as to constitute the greater mass of the 
central part of the stipe. By their very thick walls they contrast strongly with the 
adjoining cells; (tab. 25, fig. 1—4). 
In general this is the structure of the stipe also in Ph. lorea: but in transverse 
sections of the stipe both in younger and older individuals the above-mentioned tubular 
cells are not visible. On closer examination they are certainly detected and are found 
to occupy the same position as in the preceding species, but their walls are always 
thin, not differing in thickness from the walls of the adjoining parenchymons cells 
(tab. 25, fig. 5). With regard to the cryptostomata the species Ph. dermatodea varies 
considerably. They are sometimes pretty numerous in older individuals, csarce in 
younger ones, sometimes very rare or almost absent both in younger and older spe- 
cimens. The former is usually the case in specimens from the north coast of Norway, 
the latter in specimens from other parts of the Arctic Sea. The shape and structure 
of the cryptostomata is accurately described by J. E. Ansscrouac Obs. Phyc. 3, p. 12. 
Habitat. In the Arctic Sea proper the present species occurs in company with 
other Laminariacew and is usually met with here at a depth of 2—10 fathoms on rocky 
or stony bottom. On the coast of Norway it does not belong to the proper formation 
of Laminariacee, but descends deeper than this, even to a depth of 20 fathoms. But 
it is most common here in shallow, rather exposed bays on gravelly bottom in 4—5 
fathoms. On the north coast of Spitzbergen young individuals were common in the 
winter, nor were older ones wanting during the same season. Of the other species, 
Ph. lorea, on the contrary, young specimens were most common during the summer. 
On the coast of Norway younger and older specimens are of rather the same frequency 
during the summer-months, in July and August. At Spitzbergen I have found speci- 
mens with zoosporangia in July and August, at Novaya Zemlya in July, on the north 
coast of Norway in the latter part of August and at the beginning of September. 
However, the proper season for the formation of the zoospores on the last-named coast 
appears to come somewhat later, towards September or the beginning of October. 
Geogr. Distrib. It is known from those parts of the Polar Sea which extend 
northwards of the Atlantic. Its maximum of frequency seems to be on the north coast 
of Norway, although even here it does not occur in such numbers as are comparable 
in any way with other Laminariacee. 
Localities: The Norwegian Polar Sea: Finmarken at Maasé, Gjesveer, the south 
coast of Mageré, Oxfjord and Talvik, usually local and rather scarce; at Maasé pretty 
abundant. 
The Greenland Sea: Beeren ELiland; on the north and west coasts of Spitzbergen 
local and scarce. 
The White Sea: According to Gost it is probably this species which K. v. Barr 
has taken at Tri-Ostrowa. 
Baffin Bay: the west coast of Greenland at Claushayn. 
With regard to the distribution of the two forms I can only say that the Phyllaria 
dermatodea which I found on the north coast of Norway belongs to f. typica, but that 
from the Greenland Sea and the Murman Sea to f. arctica. 
ae 29 
K. Vet. Akad. Handl. Bd. 20. N:o 5. it 
