793 



cold-boreal, that of the eastern part arctic, whilst that of the western 

 and northern parts is a mixed flora. As Jonsson intends to enter 

 more fully into a comparison with the adjacent countries, in his 

 paper on the algæ-vegetation of Iceland using this division as basis 

 I may avoid too much detail here and simply keep to tiie two 

 principal divisions: North-East and South -West Iceland. 



The total number of species mentioned by Jonsson from Ice- 

 land is 195^, Of these 195 species, 121 Rhodophyceæ and Phæo- 

 phyceæ and 44 Chlorophyceæ and Cyanophyceæ, in all 165, are 

 found on the southern and south-western part of the country, that 

 is, from LonsheiSi on the south-east coast to Låtrabjarg on the 

 north-west coast. From Låtrabjarg to Hornbjarg on the adjacent 

 coast of North-West Iceland with mixed flora, we further find the 

 following 7 species: Ceratocolaæ Hartzii, Phyllophora Brodiæi, Adino- 

 cocciis sLibciitaneiis, Piinctaria plantaginea, Monostroma groenlandicum, 

 Åcrochæte repens and Bolhocoleon piliferiim, which have hitherto not 

 been found in more southerly piaces in Iceland. With the latter 

 species the total number becomes 172. 134 of these species and 

 5 from the adjaceilt coast, 139 in alP, are also found at the 

 Færoes. 



The 76 Færoese species which are not found at South-West 

 Iceland can be divided into the following groups : 

 I. Species found at North-East Iceland : 



Laminaria færoensis, Petroderma maculiforme, Codiolum grega- 

 riiim, C. piisilliim, Phormidinni aiihinmale. 

 II. Species found at Greenland: 



Chantransia efflorescens, Harveyella mirahilis, Polysiphonia elon- 

 gata, Rhododermis elegans, Sorapion Kjellmani, Ulolhrix conso- 

 ciata, Pilinia maritima, Uluella con fluens, Vaucheria coronata, 

 Calothrix scopulorum. 

 III. Species found on the coast of North Norway: 



Erythrotrichia ceramicola, Chantransia Daviesii, Polysiphonia 

 violacea, Polysiphonia Brodiæi, Rhodomela subfusca, Callitham- 



' According to Mr. Foslie's latest determination, Lithothamnion circumscriptum 

 must be excluded from the number of species, whilst on the other hånd Chantransia 

 microscopica and Vaucheria sphærospora must be included (compare Borgesen 

 and Jonsson, 12). 



^ Of Phyllophora Brodiæi only the subspecies interrupta has been found at 

 Iceland, but the Færoese specimen is very much like it; as to Acrosiphonia, I 

 consider A. flaccida as belonging to A. hystrix (8. p. 512), and Spongomorpha lanosa 

 to be the same as Sp. vernalis (12, p. XXV). 



