765 



Together with Ectocarpiis litoralis these algae form tough, en- 

 tangled, loose-lying masses in shallow water. Besides these algae we 

 find Chorda filum, Scytosiphon lomentnriiis, Ceramium rubriim, Halo- 

 saccion ramentaceiim and sometimes also other species belonging to 

 the above mentioned Stidyosiphon-ixssociaiion. As already mentioned 

 this association together with the 5^/zc/j/os/p /7on-association perhaps 

 answers to Simmons's Ulvaceenformation. 



Th e Ha Hdrys-Associa Hon . 



As this association is but rarely found at the Faeroes, it is of 

 minor importance there. It has only been found attached to the 

 bottom within a very limited region at Glibre in Skaalefjord on 

 0stero, but as this alga is rather abundant in this locality and 

 agrees quite well with Hansteen's (38, p. 353), Boye's (6, p. 8) and 

 Gran's (36, p. 19) descriptions of their //a /zt/rys- formation, I think 

 tliat it ought to be mentioned here. It grows here on a stony bot- 

 tom at a depth of from ^/2 to 1 fathom , forming a narrow belt at 

 no great distance from the coast. The specimens are enormous, 

 almost one fathom long. It grows together with scattered specimens 

 of Laminaria digitata, L. hyperborea and L. fceroensis and Chorda fdiim. 



When I visited the tract in May 1898, I found several small 

 specimens of Punctaria latifolia, Chordaria flageUiformis, Ectocarpiis 

 Utoralis, Stictyosiphon foenicidaceus , Dictyosiphon and a great many 

 Diatoms growing epipliytically on tlie HaUdrys. 



In August (?) Simmons found it densely overgrown by Dic- 

 tyosiphon hippuroides ; he therefore calls it »the Halidrys-Dictyosiphon- 

 formation«. 



The Laminariacece-Formation on sheltered coasts. 



The La777Z77arzacecE- formation varies much on sheltered coasts. 

 Where there is no current, Laminaria fceroensis grows abundantly, 

 forming widely spread associations. But where there is a rapid cur- 

 rent, as in most sounds between the islands, L. fceroensis is wanting 

 and is replaced chiefly by L. hyperborea. 



Let us first consider the Laminaria fceroensis-SiSsocisiWon whicli 

 grows on sheltered coasts. This alga necessarily requires a habitat 

 where the sea is never disturbed. The large lamina which is often 

 several fatlioms long and easily broken would soon be torn by the 

 surf. The slender haptera and the brittle stalk would not long be 

 able to resist the strain caused by the current. 



49* 



