KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 205 



f. typica nob. 



Descr. Fucus furcatus Akesch. Fuo. et Pyciiopli. p. 107. 



Exsicc. » » Kjellm. in Abesch. Alg. Scaiid. exsicc. N:o 401. 



f. contracta nob. 



f. parviila, tliallo circn 10 cm. alto, coriaceo, dense dicliotomo; segmentis inlerioribus ad costas validas, 

 firmas leductis, superioribus alatis, oosta distincta vel subdistiucta, 3 — 4 mm. latis; receptaculis cyliuilrico-fusi- 

 formibus, siniplicibus vcl rarius fiircatis 1,5 — 2 cm. loiigis, diametro 'å mm.; scaphidiis creberrimis, minutis. 



Syn. Fucus furcatus Aresgh. Fuc. et Pycuopli. p. 107, quoad spec. Norvegica et Groenlaudica. 



Remark cm tids species. J. G. Agardii in Spec. Alg. identilies Fucus furcatus Ag. 

 with Fucus edentatus De la Pyl. To this view J. E. Aueschoug accedes on acconnt 

 of a speciraen communicated by Harvey; Fuc. et l^ycnoph. p. 109. It is however 

 contested by Ruprecht who shows F. furcatus Ag. and the alga described by Ågardh 

 under this name to be two rather distant forms which differ even so inuch that they 

 ought to be referred to different species; Alg. Och. p. 346. From this cause J. G. 

 Agardh in his survey of the species of Ftwus abandons his former view and sets down 

 Fucus edentatus De la Pyl. as specifically distinct from F. furcatus Ag. Spetsb. 

 Alg. Till. The identity of the Fucus in question, occurring on the north coast of 

 Norway, with Fucus edentatus De la Pyl. appears to me to be beyond a doubt. As I 

 have not, among the great number of specimens from Norway and the north-eastern 

 coast of North America examined by me, found any that agrees fully with Agardhs 

 figure of F. furcatus, I have th ought best to follow J. G. Agardii's låter exposition, 

 regarding F. edentatus as specifically distinct from F. furcatus Ag. 



As respects the form that I have described above under the name of f. contracta, 

 it is incontestably united by intermediate forms with the typical form, that is to say, 

 that delivered by me for distribution in Aresciioug's Alg. Scand. exsicc. Being however 

 pretty unlike this and at the same time resembling in raany respects othcr species- of 

 Fucus: F. Fueci, F. 'iiiiclonensis J. G. Ag. and F. distichus, I liave thought ht to point 

 it out specially, lest it should be described as a separate species by some one who has 

 not had an opportunity of seeing the transitions between it and F. edentatus f. typica, 

 or lead to some sort of unnatural combination of Fucus edentatus with some of the 

 species mentioned above. 



Besides these forms, f. typica and f. contracta, there is to be found on the north 

 coast of Norway even a third form which is perhaps worthy of attention, being ana- 

 logous to f. yrandifrons of F. serratus, f. vadorum of F. vesicolosus and f. pergrandis of 

 F. evanescens. However, all the specimens on which this opinion is founded being sterile, 

 I cannot here enter into details, but only wish to draw the attention of future investi- 

 gators to the subject. 



Habitat. The species is exclusively litoral, and lives within the lower part of 

 this zone, occupying a region situate between Fucus serratus on the one side and F. 

 vesicidosus and F. spiralis on the other, as has been pointed out already by Kleen. It 

 seems to prefer exposed localities and is found gregarious in large uumbers on exten- 

 sive areas of the bottom on the coast of Norwegian Finmarken. Farther southwards 



