MARINE ALGAL VEGETATION 



75 



mark. Of the remaining 23 species the greater number will cer- 

 tainly be found in Finmark. But I think it less probable that Om- 

 phalophyllum ulvaceum and Laminaria fccroensis are to be met with 

 there, while one can form no opinion as to whether the endemic 

 Icelandic species (17 and 31) exist in Finmark, as their distribution 

 outside Iceland is unknown. On the other hand I think it somewhat 

 probable that the Icelandic- Faeroese species Myrionema fceroense may 

 occur in Finmark. 



The 27 species, which are present in Finmark and absent from 

 Iceland, are the following: — 



Chantransia efflorescens. 

 C. Daviesii. 

 Harveyella mirabilis. 

 Polysiphonia elongata. 

 Spermothamnion Turned. 

 Furcellaria fastigiata. 

 Polyides rotundus. 

 Petrocelis Middendorfii. 

 Phymatolithon investiens. 

 Lithothamnion intermedium. 

 L. fornicatum. 

 Lithoderma lignicola. 

 Mvrionema foecundum. 



Ectocarpus terminalis. 

 E. nanus. 

 E. ovatus 



Myriotrichia filiformis. 

 Sphacelaria racemosa. 

 S. cirrhosa. 



Phaeosaccion Collinsii. 

 Asperococcus echinatus. 

 Delamarea attenuata. 

 Dictyosiphon hispidus. 

 Laminaria Agardhii. 

 Haplospora globosa. 

 Halidrys siliquosa. 



Chilionema reptans. 



The majority of these species may be expected to occur on the 

 coasts of Iceland, but there is less probability of Laminaria Agardhii 

 being met with there. 



If we turn to E. Iceland and compare this with the White Sea 

 we obtain the following figures : — 



E. Iceland 80 species White Sea 52 species 



not common common not common 



43 (45%) 37 (39%) 15 (16%) 



The floristic similarity is somewhat considerable, and ten of 

 the species peculiar to the White Sea are known from other parts 

 of the coast of Iceland. These ten species are Dilsea edulis, Cysto- 

 clonium purpurascens, Polysiphonia nigrescens, Delesseria alata, Ptilota 

 plumosa, Lithothamnion Lenormandi, Corallina officinalis, Dictyo- 

 siphon hippuroides, Fucus serratus, and Pelvetia canaliculata. 



Of these species, however, only an extremely small number 

 can be expected to occur in E. Iceland. 



The five species present in the White Sea and entirely absent 

 from Iceland are: — 



