759 



whicli are common and peculiar to the Laminaria lujperborea it- 

 self, a number of large and some small algæ are found in the 

 Laminaria hij per bo rea-associaiion, where the latter is less abundant. 

 Thus a rich growth of the Alaria escnienta is often found in piaces 

 with a rapid ciirrenl, down to a depth of about 5 — 6 fathoms. At 

 about the same depth, I have found enormous specimens, a fa- 

 thom long, of Chorda tomentosa in the rapid current where Haralds- 

 sund is narrowest. 



On stones and rocks below and among the Laminaria hijper- 

 borea, we often meet with different red algæ e. g. Porphyra miniata, 

 Phijllophora Brodiæi, Odonthalia dentata, and several of the algæ that 

 grow epiphytically on Laminaria hijperborea. Lastly Desmarestia 

 aculeata and D. viridis may be found abundantly down to a depth 

 of about 10 — 15 fathoms. So far as may be judged from the dred- 

 gings, these algæ form often an almost pure Des/nares//a-association. 



The Laminaria hyperborea- dissociation has already been men- 

 tioned in connection with the Færoes by Simmons, who likewise 

 writes that the »Laminaria hy perborea-f ormaiion« is the most com- 

 mon on the coast of these Isles. It is indeed only absent where the 

 bottom is sandy right up to the beach. With the exceplion that the 

 epiphytic vegetation presents slight differences, the Laminaria-yege- 

 tation of the Færoes corresponds exactly with the Laminaria-forma- 

 tion on the west coast of Norway described by Boye (6, p. 5) and 

 Hans teen (38, p. 351); compare also Ekman (17,p. 4— 5 and p. 10). 

 On the Shetland Isles I have had an opportunity of seeing a Lami- 

 nar ia-\ege{aiion which corresponds with this association. S t rom- 

 felt does not give any special account of the Icelandic Lami- 

 naria hyperborea- associaiion; but most likely a similar vegetation 

 must be found on the southern and western coasts of Iceland. 



The Lithoderma- Association. 



On the coasts of the Færoes, I have not seen this association 

 so typically developed as has been described by Kjellman (23, 

 p. 66) and Rosen vinge (45, p. 223). 



The reason is, probably, that the bottom in deeper water is ot- 

 ten of sand or mud and therefore destitute of piants. In the piaces 

 where I found this association, the bottom was covered by peb- 

 bles. Lithoderma fatiscens grew here together with some other algæ, 

 especially Florideæ , which made the vegetation look somewhat 

 variegated. 



