KONGL. SV, VET. AKABEMIENS HANDLINGAR. BAND. 20. N:0 5. 103 



Florula Discoana under the name of Melohesia 'polymorpha. But having convinced my- 

 self, through an examination of the collections of Corallines brought home by Th. M. 

 Fries from the west coast of Greenland, that L. polymorphum is really to be found in 

 Baffin Bay, I think it possible indeed that Croall's determination is quite correct. 

 Areschoug 1. c. records L. polymorphum from Spitzbergen, though with reservation. It 

 may be that it occurs really here. But as I have not seen it here myself and as it 

 was not to be found among the large collections of Lithothamnia once made here by 

 myself, and as moreover L. glaciale at certain stages of its development may exhibit 

 great outward resemblance to L. polymorphum, I consider myself justified in excluding 

 it, at least temporarily, from the Flora of Spitzbergen. That Lithothamnion piolymorphum 

 Avhich I have myself reported from the Murman and the Kara Seas, belongs to other 

 species, as I have already demonstrated. 



Habitat. The plant is properly a litoral alga, living principally in rock-pools 

 within the lower part of the litoral zone. However it descends also into the sublitoral 

 zone and is met with even at such a considerable depth as 10 — 15 fathoms. It flou- 

 rishes in exposed as well as in sheltered localities and is gregarious, although in the 

 north it does not occur in any very great masses at the same place. I know only 

 sterile specimens from the Polar Sea. 



Geogr. Distrib. This species occurs with certainty in the Atlantic as well as 

 the arctic region of the Polar Sea, although there are wide reaches of the latter, where 

 it seems to be replaced by other species. Rs maximum of frequences lies probably 

 within the Atlantic region. The question of how far it goes northwards in Baffin Bay, 

 is not yet cleared up. The northermost place where it is known Avith certainty to grow, 

 is Gjesvser, about Lat. N. 71°. 



Localities: The Norwegian Polar Sea: common and pretty plentiful both in the 

 south at Nordlanden and in the north within Tromso amt and Finmarken amt, as at 

 the town of Tromso, at Karlso, MaasQ, Gjesvajr, the south coast of MagerS (ipse), IngO, 

 Honningsvaag and Berlevaag (Foslie). 



The Siberian Sea: Pitlekay, scanty, local. 



The American Arctic Sea: Erebus and Terror Bay, Union Bay, Beachey Island, 

 Cape Spencer (?). 



Baffin Bay: The west coast of Greenland according to specimens collected by 

 Th. M. Fries; Disco Isle (?). 



Gen. Lithophyllum (Phil.) Rosan. 



Melob. p. 79; Phil. Wiegra. Arch. 1, p. 385; lira. mut. ^^^^ 



Lithophyllum Lenormandi (Aresch.) Rosan. 

 1. c. p. 85; Melobesia Lenormandi Aresch. in J. G. Ag. Spee. Alg. 2, p. 514. 



Descr. Lithophyllum Lenormandi Rosan. 1. c. p. 85. 



Fig. » » » » t. 5, fig, 16 et 17; t. 6 fig. 1, 2, ,3 et 5. 



Exsicc. Melobesia » » Hohenack. Alg. Mar. N:o 296. 



Syn. Lithophyllum Lenormandi Gobi, Algenfl. Weiss. Meer. p. 21. 

 » Melobesia Lenormandi Kleen, Nordl. Alg. p. 11. 



