KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 4] 
Geogr. Distr. As far as is known hitherto, it belongs only to the Atlantic region 
of the Polar Sea. The most northerly place where it has been found, is Maasé, about 
Bat. N. 71°. 
Localities. The Norwegian Polar Sea: Nordlanden, common and abundant; Tromsé 
amt for inst. at Tromsé and Carlsé, at the latter place plentiful; Finmarken, abundant 
in several places, as Maasé and the southern coast of Mageré. Fost has communi- 
cated to me specimens collected at Honningsvaag and Lebesby. 
. 
Lithothamnion Ungeri, novum nomen. 
Deser. et Fig. Lithothamnion byssoides Unger Leithakalk p. 19—20, tab. 5, fig. 1—8. 
Remark on the determination of the species. From specimens collected on the coast 
_of Norway and preserved in the Museum of Bergen, Uncer has, under the name of 
Lithothamnion byssoides (Lam.) Phil., described and figured a Lithothamnion, also found 
in the Arctic Sea by Mr M. Fosrtm and kindly sent to me. The coincidence of the 
specimens I have at my disposal, with the description and figures of UNGeEr is palpable. 
But on the other hand, it is evident that this plant cannot by any means be identical 
with that which goes now commonly under the name of Lithothamnion byssoides (LAM.) 
Phil. Therefore I propose that this Norwegian species take the name of L. Ungeri 
after him who first described and figured it in a recognizable manner. To the descrip- 
tion of Uncer I have nothing essential to add. The specimens I have had an oppor- 
tunity of examining, are sterile. 
The relation of the present species to other species. With reference to its structure, 
L. Ungert approaches nearly to the preceding species. Like this, it never possesses 
occluded conceptacles of sporangia, and, besides, the arrangement of the cells is the 
same in both. It differs distinctly by its strongly developed, crustaceous hypothallus, 
by its denser ramification, with shorter, much finer, and less compound branches. It 
can scarcely be confounded with any known species of the genus. 
Hab. Unknown to me. The specimens, taken in September, are sterile. 
Geogr. Distr. The Atlantic region of the Polar Sea. 
Locality. The Norwegian Polar Sea: Tromsé amt near the town of Tromsé (Fosix) 
Lithothamnion Alcicorne nob. 
L. fronde initio affixa, demum libera in fundo jacente,’ flavescente, apicibus pulchre roseis, 4—5 cm. 
alta, decomposito-subpalmatim-ramosa; ramis ex axi primario brevissimo flabellatim egredientibus, vel omnino 
liberis vel in planta provectiore state plus minus coalitis, subcompressis, lavibus, extremis brevioribus, ecylin- 
dricis vel compressis, apicibus rotundatis; conceptaculis sporangiferis superticialibus, numquam innatis, planato- 
hemisphericis, sat magnis, infra apices ramulorum sparsis, conceptaculis sporocarpiferis, elevatis, conicis, acutis, 
apice perforatis intermixtis. Sporangiis quaternas sporas foventibus, 250 «. longis, LOO uw. crassis. Tab. 5, 
fig. 1—8. 
Description. External shape of the plant. I have not seen any attached specimens 
of this species, but those I have at my disposal through the kindness of Mr M. Fostie, 
