KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 140 
Remark on the determination and the synonymy of this specics. In the above attempt 
to group the arctic forms of this many-shaped species the forms constitute two series. 
The former of these, comprising f. typica and sarniensis, is characterized by the ma- 
jority of the secondary axes of the frond being formed by repeatedly subdichotomous 
branching, the latter, comprehending f. prolifera and f. angustifolia, vy all, or most, 
secondary axes being so-called prolifications. The specimens of the typical form, 
most common in the arctic parts of the Polar Sea, are very magnificent, large, and 
high-coloured. They are undoubtedly the largest Mloridew of this region. The typical 
form occurs more rarely in the habit represented by pl. 217 in Hary. Phyc. Brit. and 
nained by Harvey f. marginifera. It is easily seen, however, that the diagnosis, borrowed 
from Stackh. Ner. Brit. (p. 54), which accompanies the figure in Harvey does not 
accord with the plant delineated The forms sarniensis and prolifera are somctimes 
rather difficult to distinguish from each other. The form distributed by ArescuouG in 
his work of Scandinavian exsiccates under the name of f. sobolifera approaches more 
nearly to f. sarniensis, especially to ( tenuissima. I have assumed that Kirzinc by his 
Sphewrococcus palnatus y prolifer means the arctic broad-fronded, high-coloured form 
(@ purpurea nob.). But I am not certain of it. This form is nearly related to what I 
have called f. prolifera pallida, which is common in Kattegat and Skagerack and is 
possibly to be found also in the southern part of the Norwegian Polar Sea. However, 
( pallida differs so much in colour as to deserve special mention. Another form, very 
beautiful, which connects the two series with each other, but accords most closely with 
f. prolifera, is f. angustifolia, a prolificating form with narrow frond, that attains some- 
times half a foot in length and becomes much branched by repeated prolifications. 
Sometimes it is very little, 1—2 inches long, with very small prolifications. It is pro- 
bably a stunted form either of f. angustifolia or of f. prolifera that J. G. AGarpu has 
named f. microphylla in his list of the alge brought home from Spitzbergen by the 
Swedish expedition of 1868 and distributed by him. 
Habitat. In the Greenland Sea and the eastern part of the Murman Sea as well 
as on the west coast of Sweden the present species is sublitoral, in the Norwegian 
Polar Sea it is litoral. I do not know how it is in the other parts of the Arctic Sea. 
In the first-mentioned seas it grows on stony bottom at a depth varying between 3, 
seldom less, and 15 fathoms, sometimes gregarious, sometimes scattered together with 
Fucoidee. On the coast of Norway it keeps chiefly to the lower part of the zone of 
the Fucacew, usually covering stones and rocks in large, dense masses together with 
Fucaceew. At more free places where it is less covered and oppressed by other algw, 
it appears here in its typical form or as a large-sized f. prolifera ¢« purpurea. When 
growing, on the contrary, among dense masses of Mucacew, by which it is covered at 
low-tide, it assumes the habit charakteristic of f. sarniensis, angustifolia, or dwarfed 
prolifera. It occurs chiefly on exposed coasts, but enters also into deep bays, even 
where the water is comparatively little salt during some parts of the day. Cp. 
Kieen, Nord]. Alg. p. 17. On the north coast of Spitzbergen the present plant is 
developing all the year round, even in winter. During the whole time from the 
beginning of November to May, accordingly during the whole dark and cold season, | 
