KONGL. SV. VKT. AKADEMIENS HANDLINGAR. BAND 20. N:u 5. 301 



Habitat. The specimens in my ])ossession were dredged in the lowest part of the 

 sublitoral zone in about 20 tathorns. They were attached to stones. All were sterile 

 when taken in the iniddle of August. 



Locality; The Norwegian Polar Sea: Finmarken at Maasö. 



Mon östro ma Blyttii (Aresch.) Witte. 



Moiiosti'. p. 49. Ulva Blyttii Arescu. iu Fr. Sura. Veg. p. 129. 



Descr. Monostroma Blyttii Wittr. 1. c. 



w » Kleen, Norell. Alg. p. 42. 



Fig. » » Kjellm. Spetsb. Thall. 2, t. 4, fig. 1—7. 



Exsicc. » » Kjellm. in Aresch. Alg. Scaiid. exsicc. N:o 423 et WrrTR. ot Nordst. Alg. exsicc. 



N;o 44. 

 Syn. Monostroma Blyttii Kjellm. Spetsb. Thall. 2, p. 49; Algeuv. Murra. Meer. p. 52. 

 » » Kleen, Nordl. Alg. p. 42; excl. syn. 



Ulva Blyttii Aresch. Phyc. Soand. p. 412. 

 » fusca J. G. Ag. Grönl. Alg. p. 110; fide spec. 

 » lactuca(?) J. G. Ag. Spetsb. Alg. Progr. p. 2; Bidr. p. 11)?). 

 » » (?) LiNDBL. Bot. Not. p. 158(?), 



1) latissima (?) Ashm. Alg. Hayes, p. 96 (?). 

 » » » Ckoall, Fl. Disc. p. 461 (?). 



» )i » DiCKiE, Alg. Sutherl. 1, p. 144; Alg. Cumberl. p. 239; Alg. Nares, p. 7 (?). 



» rigida Sommerp. Suppl. p. 185. 



Remark on the synonymy. I have assumed that the TJlva latissima reported from 

 Baffin Bay is the present species, because U. latissima, though said by Croall and 

 DiCKiE to be coinmon on the coast of Baffin Bay, is completely wanting in the collec- 

 tions from Greenland in the Copenhagen Museum, while of Monostroma Blyttii which is 

 not reported from Baffin Bay either by Dickie or Croall there is to be found there 

 a great qviantity of very luxuriant specimens reminding one of U. latissima. 



Habitat. In the Arctic Sea proper on the coasts of Spitzbergen and Novaya 

 Zemlya this species is always sublitoral, growing scattered at a depth of 3 — 5 fathoms 

 both on exposed and sheltered coasts, attached usually to small stones, sometimes to 

 alg-di. On the north coast of Norway it is, on the contrary, generally litoral, usually 

 occurring in the upper part of this zone, especially in rock-pools with numbers of 3Iy- 

 tilus edulis, both on exposed and sheltered coasts, in salt or somewhat brackish water, 

 attached to stones or algse. Hovvever, it is occasionally met with also here within the 

 sublitoral zone, but then it lies loose on the bottom. Such specimens attain sometimes 

 a considerable size. There is one in my collections of 30 cm. in length by 40 cm. in 

 breadth. When it lives in such localities, viz. at the mouths of streamlets and rivers, where 

 the water is somewhat brackish, it is yellowish green in colour and of looser consi- 

 stency. It is generally gregarious on the coast of Scandinavia and contributes essen- 

 tially to mark the aspect of the litoral vegetation. 



Geogr. Distrib. It belongs to those parts of the Polar Sea which lie north of 

 the Atlantic. On the coast of Norway it is very abundant, as seems to be the case 



