KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 93 



Geogr. Distr. The Atlantic region of the Polar sea. Within the arctic region it 

 has not as yet been found. 



Locality. The Norwegian Polar Sea : Tromsö amt near the town of Tromsö, the 

 only place where it is known to occiir. Here it has been found by M. Foslie. 



Lithothamnion Norvegicum Aresch. (nob). 



Descr. Lithothamnion caloareum var. norvegicum Arksch., Obs. Phyc. 3, p. 4 — 5. 

 Fig. Lithothamnion norvegicum tab. nostra 5, (ig. 9 — 10. 



Remark on the determination of the species. J. E. Areschoug 1. c. has described, 

 under the preceding combination of names, a plant from the southwest coast of Norway, 

 that has also been found in the Polar Sea. On pl. 5, I have given figures of one 

 specimen from the south of Norway (fig. 9) and of another from the Polar Sea (fig. 10). 

 Judging from the fäet that no overgrown sporangia are to be found on sections of 

 older frondal portions, the plant with regard to the inner structure belongs to that 

 group of Lithothamnia which possesses external conceptacles of sporangia. Areschoug 

 considers this plant to be a local form of Melobesia (Nulli2Jora) calcarea Ell. et Sol., 

 occurring on the coasts of England and ligured by Harvey (Phyc. Brit.) and Johnston 

 (Brit. Spong. Lith.) It is certainly possible that this may indeed be the case, but the 

 statement of Areschoug »forma M. calcarea quam depinxit et descripsit Harvey (est 

 forsan maxima et magnopere evoluta) a nostra valde abborrens» being clearly quite 

 correct, and the Norwegian specimens being unlike those figures of NuUipora calcarea, 

 much diflfering from one another and possibly designating different species, which 

 Johnston gives, I consider myself entitled to regard the above-mentioned plant, found 

 on the coast of Norway, as a distinct species separated from Melobesia calcarea Harvey 

 and NuUipora calcarea Johnston. 



Hah. It grows, spreading stratiformly, in 10 — 15 fathoms water. Cf. Areschoug 

 I. c. Only sterile specimens are known. 



Geogr. Distr. This species belongs only to the Atlantic region of the Polar Sea, 

 and seemingly only to its most southerly part. It has not been found to the north 

 of Nordlanden. 



Locality. The Norwegian Polar Sea: Nordlanden at Lödingen (Foslie). 



Lithothamnion glaciale nob. 



L. fronde deraum crustara formante validam circura lapides vel conchas effusam e roseo flavescetitera, 

 plus minus lobatam, ramos simplices, conicos, obtusos vel subcylindricos, usque 7 — 8 rara. altos, inferne dia- 

 metro usque 6 mm., scabriusoulos undique eraittentem; conceptaculis sporangiferis deraum innatis, minutis, con- 

 vexiusculis at parum prominentibus, creberrimis, nullo ordine in orusta ramisque dispositis; sporangiis binas 

 sporas foventibus, 80 — 135 //. longis, 40 — 60 /(. crassis; Tab. 2 et 3. 

 Syn. Lithothamnion calcareum Kjellm., Vinteralg. p. 64. 



» » Kleen, Nordl. Alg. p. 11. 



1) fasciculatum Aresch. Obs. Phyc. 3, p. 5 (saltem e.\ parte). 



» » DicKiE, Alg. Sutherl. 1, p. 142. (?) 



» » GoBi, Algenfl. Weiss. Meer. p. 22. 



» » Kjellm. Spetsb. Thall. 1, p. 3, Algenv. Murm. Meer, p. 7 et alibi. 



