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MARINE ALGAL VEGETATION 



59 



Rhodophyeeae. 

 Ceratocolax Hartzii. Cruoria arctica. 



Turnerella Pennyi. Lithothamnion flavescens. 



Delesseria Baerii * corymbosa. L. foecundum. 



Polysiphonia arctica. 



P b ae o p h y c e ae. 

 Omphalophyllum ulvaceum. Laminaria nigripes. 



Dictyosiphon corymbosus. 





Monostroma groenlandicum. 



Chlorophyceae. 



B. The Subarctic Group. 



Subdivision I. 



The species of this subdivision are common in the Arctic Sea, 

 and are rather common in the cold-boreal area of the Atlantic Ocean 

 as far south as the Faeroes and Nordland; some of them occur, 

 although rarely, as far south as England. 



Rhodophyceae. 

 Rhodophyllis dichotoma. Peyssonellia Rosenvingii. 



Halosaccion ramentaceum. Lithothamnion tophiforme. 



Ptilota pectinata. L. laeve. 



Rhodochorton penicilliforme. Clathromorphum compactum. 



Ph 



Lithoderma fatiscens. 

 Ralfsia ovata. 

 R. deusta. 



Myrionema globosum. 

 M. Laminariae. 

 Streblonema aecidioides. 

 Sphacelaria britannica. 



Chi 



Chlorochytrium Schmitzii. 



Monostroma undulatum. 



M. fuscum. 



Ulothrix consociata v. islandica. 



U. subflaccida. 



ae o p h y c e ae. 



Chaetopteris plumosa. 

 Coilodesme bulligera. 

 Saccorrhiza dermatodea. 

 Laminaria faeroensis. 

 L. digitata. 

 Alaria Pylaii. 



o r o p h y c e ee. 



U. pseudoflacca. 

 Acrochaete parasitica. 

 Urospora Hartzii. 

 Acrosiphonia hystrix. 

 A. penicilliforme. 



Subdivision II. 



This subdivision includes species, which are either common 

 in the Arctic Sea and the North Atlantic from western France — 

 England northward, or which, if not common, are at least all 

 equally frequent. 



