88 KJELLMAN, THE ALGM OF THE ARCTIC SEA. 



GeograjMcal distribution. It belongs properly to that region of the Arctic Sea 

 which lies within the northern limits of the Atlantic, but it is known also from the 

 White Sea and the western part of the Murraan Sea. Its northernmost locality is 6jesva?r 

 near North Cape about Lat. N. 71°. It attains its maximum of number of individuals 

 in the southern part of the Norwegian Polar Sea. In 111. Alg. p. II. the species is said 

 to have been found at Nova3'a Zemlya by K. v. Baer. Not having seen it there my- 

 self, and GoBi, who has examined the Russian collections of alg£E, not reporting it from 

 that locality, I suppose this statement to have arisen from sorae mistake. Areschoug 

 in J. G. Ag. Spec. Alg. II. p. 785 mentions the species as occurring »ad öras maris 

 glacialis cum lapponicas tum sibiricas». The latter region ought surely to be excluded. 

 I could not detect any trace of it along the coast of Siberia. There are no sure state- 

 ments about the occurrence of the species in other parts of the Arctic Sea ^). 



Localities: The Norwegian Polar Sea; Nordlanden, /. typica, common and plentiful; 

 Finmarken, local and scarce at Oxfjord, (/. robusta), Maasö and Gjesv^er, {f.fiexilis), the 

 south coast of Magerö, (/. typica). 



The White Sea, probably rare and scarce. 



The Murman Sea on the coast of Cisuralian Samoyede-land, (/. flexilisf). 



Gen. Lithothamnion Phil. 



Wiegm. Arcli. I. op. 387. 

 Lithothamnion soriferum nob. 



L. tVonde pilam in fundo liberani jacentem, spli?ericam vel subsphpericara, diaraetro usque 8 era., colore 

 roseo-purpureani ronuaute, decomposito-subdiohotoiue raraosissiinn; ramis e centi'0 solido, exigiio, undique egre- 

 dientibus, vel omuiuo liberis vel in planta adulta inferne plus minus coalitis, teretibus vel subcorapressis, Ifevibus, 

 extrerais elongatis, aequalibus vel apicem versus subattenuatis, apicibus rotiindatis; conceptaculis sporangiferis 

 superficialibus, numquam innatis, minutis, convexiusculis at parum promiuentibus, infra apices raraulorura re- 

 giones fere definitas occnpantibus, perpaueis vel nnmerosis; sporangiis quaternas sporas foventibus. 95 u. longis, 

 20 f.1. crassis. Tab. 1. 



Syn. Lillinthamnion fascieulatum Kleen, Nordl. Alg. p. 11. 



Description. The frond forms rather regularly spherical masses, that attain even 

 S cm. in diameter, with a strong colour, between purplisli aiul rosy. I have examined 

 a great many specimens, but I have not found any oiie that had developed itself on 

 or around a stone or any other härd object. The solid central raass both in young 

 individuals, pl. I. fig. 1, 2, 3, 5, and in older fully developed ones fig. 4, is insignificant, 

 which shows that ramification sets in at the very earliest stage of growth. The frond 

 is repeatedly subdichotoraously branched, with axes of at least three orders. The branch- 

 systems issue in all directions from the centre of the frond, and can be followed in 

 their whole length, althuugh they are more or less anastomosing below. This anasto- 

 mose has taken place dnring the growth of the plant. The branch-systems, some diffe- 



') For fiirtlier particuiars on the distribution of the species the reader is here as well as below referred to 

 the works of tiie authors quoted under each species in tlie list of synonyms. 



