62 



H. JONSSON 



Ectocarpus fasciculatus. 

 E. Hinksiae. 

 Sphacelaria radicans. 

 S. olivacea. 

 Phyllitis zosterifolia. 

 Dictyosiphon Ekmani. 

 D. Mesogloia. 

 D. Chordaria. 



Codiolum Petrocelidis. 

 C. pusillum. 



Enteromorpha aureola. 

 Prasiola polyrrhiza. 

 P. furfuracea 

 P. stipitata. 



Plectonema norvegicum. 



Castagnea virescens. 

 Laminaria saccharina. 

 L. hyperborea. 

 Fucus spiralis. 

 F. serratus. 

 Pelvetia canaliculata. 

 Alaria esculenta. 



C h 1 o r o p h y c e as. 



Entoderm a Wittrockii. 

 Acrochsete repens. 

 Ochlochsete ferox. 

 Acrosiphonia albescens. 

 A. flabelliformis. 

 Cladophora glaucescens. 



Cyanophycese. 



E. The Warm-Boreal Group. 



The majority of the species referred to this group extend at least 

 as far south as the Mediterranean and the Atlantic coast of North 

 Africa. According to the different distribution northward the group 

 is divided into three parts of which only the one reaches as far 

 north as S. Iceland. 



1. Species extending as far north as S. Iceland, the Faeroes and 

 Northern Norway, and at least as far south as the Mediterranean 

 and North Africa. 



Rhodophycese. 



Chondrus crispus. Callithamnion scopulorum. 



Lomentaria clavellosa. Ceramium arborescens. 



Plocamium coccineum. Cruoria pellita. 



Bonnemaisonia asparagoides. 

 Pterosiphonia parasitica. 



Desmarestia ligulata. 



Enteromorpha Linza. 

 Phormidium autumnale. 



Phseophycese. 



Leathesia difformis. 



Chlorophycea?. 

 Cyanophycese. 



According to the above the number of species in the groups is 

 as follows: — 



