KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 205 
f. typica nob. 
Deser. Fucus fureatus Arescu. Fue, et Pyenoph. p. 107. 
Kusice. » » KspLuM. in Arescu. Alg. Scand. exsice. N:o 401. 
f. contracta nob. 
f. parvula, thallo cirea 10 em. alto, coriaceo, dense dichotomo; scgmentis inferioribus ad costas validas, 
firmas reductis, superioribus alatis, costa distincta vel subdistincta, 3—4 mm, latis; receptaculis cylindrico-fusi 
formibus, simplicibus vel rarius fureatis 1,5—2 cm. longis, diametro 3 mm.; scaphidiis creberrimis, minutis. 
Syn. Fucus fureatus Argescu. Fue. et Pyenoph. p. 107, quoad spec. Norvegica et Groenlandica. 
Remark on this spesies. J. G. AGarpu in Spec. Alg. identifies Mucus furcatus AG. 
with Mucus edentatus De La Pyt. To this view J. E. ArescuouG accedes on account 
of a specimen communicated by Harvey; Fuc. et Pycnoph. p. 109. It is however 
contested by Ruprecur who shows f. furcatus AG. and the alga described by AGanrpu 
under this name to be two rather distant forms which differ even so much 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 Mucus abandons his former view and sets down 
Fucus edentatus De ta Py. as specifically distinct from /. furcatus AG. Spetsb. 
Alg. Till. The identity of the Fucus in question, occurring on the north coast of 
Norway, with Mucus edentatus Du LA Py. appears to me to be beyond a doubt. As | 
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 AGarpu’s 
figure of Ff. furcatus, I have thought best to follow J. G. AGarpu’s later exposition, 
regarding I. edentatus as specifically distinct from /. furcatus Ac. 
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 ArescuouG’s Alg. Scand. exsice. Being however 
pretty unlike this and at the same time resembling in many respects other species of 
Fucus: F. Fueci, F. miclonensis J. G. Ac. and Ff. distichus, 1 have thought fit 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. edentutus f. typica, 
or lead to some sort of unnatural combination of Mucus edentutus 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. grandifrons of FP. serratus, f. vadorum of FP. 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 /, 
vesiculosus and F. spiralis on the other, as has been pointed out already by Kunen. It 
seems to prefer exposed localities and is found gregarious in large numbers on exten- 
sive areas of the bottom on the coast of Norwegian Finmarken. Farther southwards 
