KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 91 



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 Maasö, about 

 Lat. N. 71°. 



Localities. The Norwegian Polar Sea: Nordlanden, coininon and abundant; Tromsö 

 amt for inst. at Tromsö and Carlsö, at the latter place plentiful; Finmarken, abundant 

 in several places, as Maasö and the southern coast of Magerö. Foslie has communi- 

 cated to me specimens collected at Honningsvaag and Lebesby. 



Lithothamnion Ungeri, novum nomen. 

 Descr. 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, Unger has, under the name of 

 Lithotluimvion byssoides (Lam.) Phil., described and figured a Lithothamnion, also found 

 in the Arctic Sea by Mr M. Foslie and kindly sent to me. The coincidence of the 

 specimens I have at my disposal, with the description and tigures of Unger 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 hyssoides (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 Unger I have nothing essential to add. The specimens I have had an oppor- 

 tunity of examining, are sterile. 



The relation of the 2)resent species to other species. With reference to its structure, 

 L. Ungeri 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. 



Hah. Unknown to me. The specimens, taken in September, are sterile. 



Geogr. Distr. The Atlantic region of the Polar Sea. 



Locality. The Norwegian Polar Sea: Tromsö amt near the town of Tromsö (Foslie) 



LithothamnionAlcicorne nob. 



L. fronde initio affixa, denaum libera in fundo jacente, tlavescente, apicibus pulchre roseis, 4 — 5 cm. 

 älta, decomposito-subpalmatim-ramosa; ramis ex axi priraario brevissimo fiabellatim egredientibns, vel omnino 

 liberis vel in planta provectiore setate plus minus coalitis, subcompressis, laevibus, extremis brevioribus, cylin- 

 dricis vel compressis, apicibus rotundatis; conceptaculis sporangiferis superticialibus, numquam innatis, planato- 

 hemisphseriois, sat magnis, inträ apices raraulorura sparsis, conceptaculis sporocarpiferis, elevatis, conicis, acutis, 

 apice perforatis intermixtis. Sporangiis quaternas sporas foventibus, 250 u. longis, 100 /^i. crassis. Tab. 5, 

 fig. 1-8. 



DescrijHio?!. 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. Foslie, 



