KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 20. N:0 5. 137 
Syn. Fucus Quercus Pan. Sib. Reise 3, p. 34. (?) 
» rubens Gunn. Fl. Norv. 2, p. 69. 
» sinuatus R. Br. in Scoressy, Account 1, App. 5. 
» sintosus ScoresBy, Account 2, p. 151. 
) » y. Wa. Fl. Lapp. p. 491. 
Phycodrys sinuosa ZeuLer, Zweite d. Polarf. 2, p. 86. 
Remark on the arctic forms of this species. Delesseria sinuosa is one of the com- 
monest alex of the Polar Sea and occurs in a great many varieties. These may how- 
ever, I think, be arranged under the three above-mentioned forms, which were di- 
stinguished long ago. For I have convinced myself that the form I have formerly 
called f. angusta, is to be referred to f. lingulata Ac. The most common of the forms 
is the D. sinuosa of the older authors. In certain parts of the Polar Sea it attains a 
considerable size and is surely to be reckoned among the most magnificent algw of 
this sea. I have seen specimens more than 30 cm. long, with leaf-shaped branches of 
even 18 cm. in length, by 8—4 cm. in breadth. Another form which approaches most 
nearly, although it never quite coincides with, the f. quercifolia common in Skagerack, 
is less often to be observed. F. lingulata is more common, differing, when most sharply 
marked, most considerably from the other forms, with which it is however connected 
by intermediate conditions. Such a transition to f. typica, extremely pretty and charac- 
teristic, is the variety recorded by Kieren from Nordlanden. Other intermediate forms, 
that I have taken at other places in the Arctic Sea, resemble so closely’ the figure 
Kirzine gives of D. Lyall in Tab. Phyc. 16, t. 14, that they cannot be distinguished 
in habit from this species. I have pretty often found individuals of f. léngulata with 
some, or most, or all branches of the last order or the last order but one filiform, 
upwards of 3—4 em. long. These branches are sometimes terete in their whole length, 
sometimes flattened at the tip. Some specimens found at Spitzbergen lying loose on 
loamy bottom are especially remarkable in this respect. HARvey mentions such spe- 
cimens from the coasts of Great Britain, cp. 1. c. Even the typical form has some- 
times such branches of the last order, but these are shorter. 
Habitat. This plant everywhere in the Polar Sea is sublitoral or elitoral. It occurs 
usually in 10—20 fathoms, sometimes in more shallow water, 1}—2 fathoms deep, or 
at very great depths. It has been dredged at Spitzbergen quite fresh in 85 fathoms. 
When growing in shallower water, it belongs to the formation of Laminariacew, in 
deeper places it is mostly found in company with Odonthalia dentata, Polysiphonia are- 
tica, Phyllophora interrupta, Ptilota pectinata and some others. It prefers exposed coasts 
and a bottom of solid rock, but is also met with in the interior of deep bays and on 
bottom formed of pebbles, shells and Lithothamnia. 
During the earlier part of the winter only older specimens were to be found on 
the north coast of Spitzbergen, but from the beginning of January young individuals 
became common. Although in the older ones the looser parts of the frond were more 
or less injured and destroyed, probably by animals, they were however in course of 
developing new parts, that were easily distinguished by their greater slenderness and their 
lighter and clearer colour. Older specimens bore tetrasporangia throughout the winter, 
’ 
K. Vet. Akad. Hand] B. 20. N:o 5, 18 
