KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 55 
northern Pacific, after these seas had received their present limits and physical nature ‘). 
It seems as if J. G. AGarpu inclined to the opinion that these species common to both 
the regions in question have had their origin in either of them and have been brought 
from this region into the other by a current continued through all the Arctic Seas. 
AGArpH says: »Though it appears to be true in general with regard to the algae, that 
the distribution of a species is confined to the limits of the same sea-current, still the 
fact of many larger alge occurring both in the Atlantic and the Pacific may possibly 
indicate the existence of a current continued through the Arctic Seas, which might 
carry alge from New-Foundland and Spitzbergen to Kamtshatka and the most northern 
isles of Western America» *). The hydrographical researches, carried on in the Arctic 
Seas by the Polar expeditions of later times, have not, however, demonstrated the exi- 
stence of such a continued current, having rather proved, on the contrary, that there is 
in the Arctic Sea a whole net-work of currents. Only by supposing a species to have 
been removed from one current into another, its occurrence both in the Pacific and 
the Atlantic could be explained from the influence of sea-currents, and such a combi- 
nation would be so complicated with regard to several species as to be hardly admissible. 
It might be supposed, indeed, that such a current existed during previous periods; but 
I do not know af any reasons for such a supposition. Without entering into this 
question in general, I will only remark, that in my opinion the occurrence of several 
alge in the northern Atlantic at the same time as in the Pacific may probably be ex- 
plained by the former distribution of water and land and the different physical con- 
ditions of the seas in former times as compared with their present state. The study 
of the present distribution of the alge of the Arctic Seas leads to such a conclusion. 
According to pretty reliable statements, the following arctic alge are to be found in 
the northern Atlantic as well as in the northern Pacific. 
Corallina officinalis? Plocamium coccineum, 
*Lithothamnion polymorphum, *Rhodymenia palmata, 
*Odonthalia dentata, *“Halosaccion ramentaceum, 
*Rhodomela lycopodioides, Dumontia filiformis, 
Polysiphonia parasitica ? Callophyllis laciniata ? 
» urceolata? *Ahnfeltia plicata, 
» fastigiata? Gigartina mamillosa? 
» atrorubescens ? Chondrus crispus? 
» nigrescens, *Ceramium rubrum, 
Delesseria alata? *Ptilota plumosa, 
M; » sinuosa, * »  pectinata, 
*Hildbrandtia rosea, Callithamnion polyspermum, 
Peyssonnelia Dubyi, » arbuscula, 
*Rhodophyllis dichotoma, Antithamnion floccosum? 
*Euthora cristata, _ americanum, 
') Cp. Eneier, Pflanzenw. p. IX—X. 
*) J. G. AGarpu, Spetsb. Alg. Bidr. p. 10. 
