76 



H. JONSSON 



Chantransia efflorescens. 

 Furcellaria fastigiata. 

 Polyides rotundus. 



Sphacelaria racemosa. 

 Laminaria Agardhii. 



With the exception of Laminaria Agardhii all these species 

 certainly may be met with on the coasts of Iceland, but in E. Ice- 

 land one can scarcely expect to find others than Chantransia efflo- 

 rescens and Sphacelaria racemosa. 



If we compare Iceland and E. Iceland with West Greenland and 

 East Greenland we get the following figures: — 



Iceland 143 species 



not common common 



62 (36%) 81 (48°/o) 



Iceland 143 species 



not common common 



79 (48%) 64 (39%) 



E. Iceland 80 species 



not common common 



11 (9%) 69 (58%) 



E. Iceland 80 species 

 not common 

 23 (21 %) 



West Greenland 108 species 

 not common 



27 (16%) 



East Greenland 85 species 



not common 



21 (13%) 



West Greenland 108 species 



not common 



39 (33%) 



East Greenland 85 species 



not common 



28 (26 %) 



common 



57 (53%) 



The species present in Iceland and absent from West Greenland 

 are the following: — 



Porphyropsis coccinea. 

 Chantransia Alariae. 

 Phyllophora membranifolia. 

 Ahnfeltia plicata. 

 Chondrus crispus. 

 Gigartina mamillosa. 

 Cystoclonium purpurascens. 

 Lomentaria rosea. 

 L. clavellosa. 

 Plocamium coccineum. 

 Delesseria alata. 

 D. sangvinea. 



Bonnemaisonia asparagoides. 

 Polysiphonia fastigiata. 

 P. nigrescens. . 



Pterosiphonia parasitica. 

 Odonthalia dentata. 

 Callithamnion scopulorum. 

 C. Arbuscula. 

 Plumaria elegans. 



Ptilota plumosa. 

 Ceramium acanthonotum. 

 C. Deslongchampii. 

 C. fruticulosum. 

 C. circinnatum. 

 C. arborescens. 

 C. atlanticum. 

 Rhodochorton minutum. 

 R. repens. 



Dumontia filiformis. 

 Dilsea edulis. 

 Petrocelis Hennedyi. 

 Cruoria pellita. 

 Rhododermis parasitica. 

 Phymatolithon polymorphum. 

 Lithothamnion Lenormandi. 

 L. flavescens. 

 L. Ungeri. 



Lithophyllum Crouani. 

 Dermatolithon macrocarpum. 



