KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 20. N:0 5. 50] 
Habitat. The specimens in my possession were dredged in the lowest part of the 
sublitoral zone in about 20 fathoms. They were attached to stones. All were sterile 
when taken in the middle of August. 
Locality; The Norwegian Polar Sea: Finmarken at Maas. 
Monostroma Blyttii (Arescu.) Wirrr. 
Monostr. p. 49. Ulva Blyttii Arescu. in Fr. Sum. Veg. p. 129. 
Descr. Monostroma Blyttii Wirrr. 1. ec. 
» » KusEN, Nordl. Alg. p. 42. 
Fig. » » KseLuM. Spetsb. Thall. 2, t. 4, fig. 1—7. 
Heasice. » » KJELLM. in Arescu. Alg. Scand. exsicc. N:o 423 et Wirrr. ct Norvsr. Aly. exsice. 
N:o 44. 
Syn. Monostroma Blyttii KypLum. Spetsb. Thall. 2, p. 49; Algenv. Murm. Meer. p. 52. 
y » Keen, Nord]. Alg. p. 42; excl. syn. 
Ulva Blyttii Arescu. Phyc. Scand. p. 412. 
» fusca J. G. Ac. Gronl. Alg. p. 110; fide spec. 
» lactuca(?) J. G. Ac. Spetsb. Alg. Progr. p. 2; Bidr. p. 11 )?). 
» »  (?) LinpB1. Bot. Not. p. 158 (), 
»  latissima (?) Asam. Alg. Hayes, p. 96 (?). 
» » » CroaL, Fl. Disc. p. 461 (?). 
» » » Dicxiz, Alg. Sutherl. 1, p. 144; Alg. Cumberl. p. 239; Alg. Nares, p. 7 (?). 
»  yigida Sommerr. Suppl. p. 185. 
Remark on the synonymy. I have assumed that the Ulva latissima reported from 
Baffin Bay is the present species, because U. /atissima, though said by Croary and 
Dickie to be common on the coast of Baffin Bay, is completely wanting in the collec- 
tions from Greenland in the Copenhagen Museum, while of Monosiroma blyttii which is 
not reported from Baftin Bay either by Dickie or Croat there is to be found there 
a great quantity of very luxuriant specimens reminding one of UL’. 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 
alow. 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 J/y- 
tilus edulis, both on exposed and sheltered coasts, in salt or somewhat brackish water, 
attached to stones or alge. However, 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 
