152 Simmons, Hemarks about tlie Helations of tlie Floras etc. 
Laminaria fissilis 
Asperococcus bullosus 
Elachista lubrica 
Myrionema strangulans 
ScytosipJton attenuatus 
PMoeospora pumila 
CIadostephus spongiosus 
Stupocaulon scoparium 
Gleothamnion palmelloides . 
Wken tliese 31 species are excluded tlie number of arctic 
species slionld consequently only be 103 (51 brown and 52 red), 
but we now know 159 species (84 brown, 75 red) from tke 
arctic regions, as can be seen in tlie following list (Table I). 
Tliis is mostly due to Rosenvinge, wko in liis works abont 
tke marine algae of Greenland (42, 43) bas treated all tlie rick 
collections brougkt konie from tkat country by tke nnmerous 
danisk 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). My own small 
collections from Jones Sound, made during tlie second Xor- 
wegian Polar Expedition I regret not to liave liad time to 
determine as yet. Still I kardly tkink tkere will be any con- 
siderable additions to tke flora of tke Polar Sea as a wliole, 
only some species not previously found in tlie american part 
of it. 
As tke result of tke tkeoretical studies of Kjellman it 
appears, tkat tke Polar Sea lias its own ckaracteristic flora, 
notwitkstanding tke appearence of most of its species also 
outside tlie arctic seas, and tliat tke original Ironie of tke present 
arctic marine flora must be souglit in tke very ice-abounding 
Polar Sea itself. As far as I can understand, lie tliinks tkat 
tke algae, or most of tkem at least, liave, even if tlieir soutliern 
limit became very muck expanded during tke iceäge, never 
entirely quitted tke present arctic regions. About tlie migration 
of tlie flora during tke iceage ke says very little, as also about 
its relation to tke tertiary flora of tlie same area, I must especially 
point out tliis fact as later writers seern to liave quite 
misunderstood kirn. Tke most important of tliese is Reinke 
(40), wko gives a clear specification of tke different stages in 
tke evolution of tlie floras of tlie Polar Sea and tke Atlantic. 
He speaks of a liigkly uniform flora tkat lived during most of 
tke tertiary time in tlie nortkern Atlantic, as is unquestionably 
proved by tke small differences tkat prevail even now on botk 
sides of tkat ocean. Tkis flora kad its nortkern limit at a 
landbridge tkat lay along tke line now niarked by its renmants 
tke Faeroes and Iceland. Xortli of tkis land existed anotker 
flora, even tkat probably uniform, in tlie present arctic sea. But 
in tertiary time tkere also ruled a warmer climate, and, wlien 
against tke end of tke tertiary period tke bridge was broken, a 
mixing of tke two floras began. How far tkis intercliange of 
