774 



arbitrariness, partly because we know so very little as yet about the 

 distribution of many algae, partly because several algae are distri- 

 buted so as to make it almost equally justifiable to refer them to 

 different groups. Whilst Reinke and Kuckuck leave the Chloro- 

 phycece and the Cijanophijcece out of consideration , as our know- 

 ledge of these plants is especially defective, I side with Rosen- 

 vinge's opinion, however, that it is more correct to mention them 

 here, as the species belonging to these orders are as important 

 from a phytogeographical point of view as those of the Rhodo- 

 phycece and Phceophycece. The species hitherto found only on the 

 Faeroes are all referred to the cold-boreal group. 



SUMMARY OF THE F^ROESE MARINE ALG^. 



I. RhodophyceaB. 



83 species. 

 The arctic group. Ptilota plumosa. 



species. 



B. The subarctic group. 

 Subdivision 1. 6 species. 



Rhodophyllis dichotoma. 

 Halosaccion ramentaceum. 

 Ptilota pectinata. 

 Rhodochorton penicilliforme. 

 Phymatolithon compactum. 

 Lithothamnion laeve. 



Subdivision 2. 14 species. 



Porphyra miniata. 

 Conchocelis rosea. 

 Chantransia efflorescens. 



— virgatula. 



Harveyella mirabilis. 

 Phyllophora Brodiaei. 

 Actinococcus subcutaneus. 

 Euthora cristata. 

 Rhodymenia palmata. 

 Delesseria sinuosa. 

 Rhodomela lycopodioides. 

 Odonthalia dentata. 



Lithothamnion glaciate. 



C. The boreal-arctic group. 

 10 species. 



Bangia fuscopurpurea. 

 Porphyra umbilicalis. 

 Chantransia secundata. 

 Ahnfeltia plicata. 

 Polysiphonia elongata. 

 Antithamnion Plumula. 

 Ceramium rubrum. 

 Rhodochorton membranaceum. 



— Rothii. 



Hildenbrandia rosea. 



D. The cold-boreal group. 

 38 species. 



Erythrotrichia ceramicola. 

 Porphyra coccinea. 

 Chantransia Alariae. 



— Daviesii. 



Choreocolax Polysiphoniae. 

 Gigartina mamillosa. 

 Phyllophora membranifolia. 



