152 
Simmons, Remarks about the Relations of tlie Floras etc. 
Laminaria, fissilis 
Asperococcus bullosus 
Elachista lubrica 
Myrionema st rangul ans 
Scytosiphon attenuatus 
Pliloeospora pumila 
Cladostephus spongiosus 
Stupocaulon scoparium 
Gleothamnion pahnelloides. 
^ hen these 31 species are excluded tlie number of arctic 
species should consequently only be 103 (51 brown and 52 red), 
but we now know 159 species (84 brown, 75 red) from the 
arctic regions, as can be seen in the following list (Table I). 
Tliis is mostly due to Rosen vinge, wlio in bis works about 
tlie marine algae of Greenland (42, 43) has treated all the rieh 
collections brought home from that country by the numerous 
danish investigators of later years. Smaller but still important 
contributions are made by Wille (53), Asa Gray (23), Farlow 
(18), Ostenfeld (37) and Jönsson (27, 28). Mv own small 
collections from Jones Sound, made during the second Nor- 
wegian Polar Expedition I regret not to have had time to 
determine as yet. Still I hardly think there will be any con- 
siderable additions to the flora of the Polar Sea as a whole, 
only some species not previously found in the american part 
of it. 
As the result of the theoretical studies of Kjellman it 
appears, that the Polar Sea has its own characteristic flora, 
notwitlistanding the appearence of most of its species also 
outside the arctic seas, and that the original home of tlie present 
arctic marine flora must be sought in the very ice-abounding 
Polar Sea itself. As far as I can understand, he thinks that 
the algae, or most of them at least, have, even if their Southern 
limit became very rauch expanded during the iceage, never 
entirely quitted the present arctic regions. About the migration 
of the flora during the iceage he says very little, as also about 
its relation to the tertiary flora of the same area. I must especially 
point out this fact as later writers seem to have quite 
misunderstood him. The most important of these is Reinke 
(40), who gives a clear specification of the different stages in 
the evolution of the floras of the Polar Sea and the Atlantic. 
He speaks of a highly uniform flora that lived during most of 
the tertiary time in the northern Atlantic, as is unquestionably 
proved by the small differences that prevail even now on both 
sides of that ocean. This flora had its northern limit at a 
landbridge that lay along the line now marked by its remnants 
the Faeroes and Iceland. North of this land existed another 
flora, even that probably uniform, in the present arctic sea. But 
in tertiary time there also ruled a warmer climate, and, when 
against the end of the tertiary period the bridge was broken, a 
mixing of the two floras began. How far this interchange of 
