- 107 — 



in the Færoes-waters and C. septentrionale on the coast of West- 

 Greenland. The first named has probably a greater area, but 

 nothing about that is known. The other species is according to 

 the collections of Kjellman (in the botanical museum in Copen- 

 hagen) also occurring on the coasts of Spetsbergen. This fact 

 together with the existence of a probably new species found by 

 Professor Arnoldi on the Murman-coast and sent to Dr. Kolderup 

 Rosenvinge seems to indicate a special arctic Ceramium-gvoup. 



Of the group with especially downwards growing zones some 

 individuals of a species related to C. circinnatum have been found 

 on the coasts of Iceland. 



The C. Eosenvingii-arborescens-group is represented by C. arbor- 

 escens found on two localities on the coasts of Iceland and by a 

 new species, C. atlanticum, occurring on the coasts of the Færoes 

 and Iceland. C. rubrum is found in all three areas but its devel- 

 opment here is very different. At the Færoes this species is evi- 

 dently thriving under good conditions as it is very common and 

 occurring in c. 12 forms or varieties. On the coasts of Iceland it 

 seems not to grow under the best (optimal) conditions, the indivi- 

 duals mostly being irregular and feebly developed. In West-Green- 

 land it has only been found once in the year 1834 by J. Vahl. 



The peculiar spreading of the species and the difference be- 

 tween the Geramium-floras in question and that of the Danish coasts 

 is best shown in the following survey. 



Denmark 



C. tenuissimum 



- strictum 



- diaphanum 



- Deslongchampii 



- vertébrale 



- Areschougii 



- fruticulosum 



G. Rosenvingii 

 - arborescens 



C. rubrum 



The Færoes 



G. acanthonotum 



G. Boergesenii 



G. atlanticum 

 G. rubrum 



Iceland 



G. acanthonotum 

 G. Deslongchampii 



G. fruticulosum 



G. circinnatum 



G. arborescens 

 G. atlanticum 

 G. rubrum 



Greenland 



G. Areschougii 

 G. septentrionale 



G. rubrum 



Cerain. acanthonotum Carm. 



Gf. Børgesen 1903, p. 387; Jönsson 1901, p. 145. Gommon on 



