292 KJELLMAN, THE ALG OF THE ARCTIC SEA. 
f. subsalsa nob. 
f. strata valde intricata, forma indefinita, e viride flavescentia vel fere albida, in fundo libera expansa 
formans; thalli axi primario distincto, latiusculo, compresso secundum totam longitudinem ramos longiores et 
breviores, simplices vel ramulosos, patentes, uncinatos, curvatos, axi primario graciliores emittente; structura 
forme typice persimilis. Tab. 31, fig. 1—3. 
Exsice. Enteromorpha clathrata var. uncinata KseLuM. in Wirrr. et Norpsr. Alg. exsice. N:o 131. 
Syn. Enteromorpha clathrata J. G. Ac. Spetsb. Alg, Progr. p. 3; Bidr. p. 11 (2). 
» » f. uncinata KyeLum. Spetsb. Thall. 2, p. 44; Algenv. Murm. Meer. p. 50. 
Ulva micrococca Gopi, Algenfl. Weiss. Meer. p. 81. 
Remark on f. subsalsa, 1 have already mentioned, in my treatise on the marine 
vegetation of the Murman Sea, that the alga recorded here under the name of Z£. 
clathrata agreed less, with regard to its structure, with the species of that name than 
with 2. micrococca Kivrz. My determination of the alga in question was based on the 
opinion pronounced by Le Joris, that the morphological characters are of more im- 
portance than the anatomical ones in determining the species of the genus Enteromor- 
pha. I must now relinquish this view, on account of the results acquired by recent in- 
vestigations. 
The alga in question closely agrees with EH. micrococca in structure. It is cer- 
tainly different from it in habit by the branching of the frond, but the degree of 
branching varying very much and even typical Z. micrococca being occasionally branched, 
I have thought best to regard the arctic plant here referred to as a form of the last- 
named species. It is distinguished from its typical form by being always more richly 
branching and by forming large, irregular, intertwisted masses lying loose on the bottom. 
Habitat. The principal form of this species grows scattered within the litoral 
zone, in sheltered localities, attached to stones. The form subsalsa is known only from 
lagoons with brackish water, often occurring in large masses so as to determine the 
character of the vegetation. It persists through the winter enclosed in ice, resuming 
its development when the ice has melted. Of the typical form I have observed speci- 
mens with zoospores in September. 
Geogr. Distrib. Known both from the Atlantic and arctic region of the Polar 
Sea. It is apparently widely distributed in the latter region and it has here its maxi- 
mum of frequency. The northernmost point where it is known to occur is Treurenberg 
Bay on the north coast of Spitzbergen Lat. N. 79° 56’. 
Localities: The Norwegian Polar Sea: (f. typica) scarce and local at Oxfjord and 
Talvik. 
The Greenland Sea: abundant in lagoons at Musselbay and Treurenberg Bay on 
the north coast of Spitzbergen. 
The Murman Sea: the coast of Russian Lapland, f. typica; the west coast of No- 
vaya Zemlya, f. subsalsa, rather plentiful in lagoons at Besimannaja Bay, and Karma-~- 
kul Bay. 
The Siberian Sea: f. subsalsa abundant at Pitlekay. 
Bafjin Bay: f. subsalsa on the west coast of Greenland at Tessarmiut. 
