KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 245 
Gen. Chorda (Sracku.) Lamour. 
Kiss. p. 46; Sracku. Ner. Brit. p. XVI; ex parte. 
Chorda filum (L.) Srackn. 
l. c. Fucus filum L. Spec. Pl. p. 1162. 
f. typica. 
Deser. Chorda filum Arescu. Obs. Phyc. 3, p. 13. 
ig. » » Harv. Phye. Brit. t. 107. 
Exsice. » »  Arescu. Alg. Scand. exsice. N:o 92. 
f. subtomentosa ARESCH. 
Obs. Phyc. 3, p. 13. 
Deser. Chorda filum ? subtomentosa Arescu. |. c¢. 
BRBSUCCH.» | > » var. tomentosa ArescH. Alg. Scand. exsice. N:o 168. 
f. crassipes nob. 
f. thallo 20—40 cm. alto, diametro 1—2 mm., flavescenti-olivacea apicem versus valde, at basim versus 
obsolete attenuato, parte basali partem apicalem crassitudine multo superante. ‘Tab. 26, fig. 16. 
Syn. Chorda filum Anrescu. Phye. Scand. p. 365 et 1. ¢. 
» » J. G. Ac. Spetsb. Alg. Till. p. 28; Grénl. Alg. p. 110. 
» » Croat, Fl. Disc. p. 457. 
» » Gost, Algenfl. Weiss. Meer. p. 74. 
» » Harv. Fl. West. Esk. p. 49. 
» »  KuJELLM. Spetsb. Thall. 2, p. 27; Algenv. Murm. Meer. p. 41 
» »  Kuren, Nordl. Alg. p. 34. 
» » Post. et Rupr. Ill. Alg. p. II. 
Fucus filum Gunn. Fl. Norv. 2, p. 10. 
» »  ScoresBy, Account. 1, p. 132. 
» » We. Fl. Lapp. p. 505. 
Scytosiphon filam J. G. Ac. Spetsb. Alg. Progr. p. 2; Bidr. p. 11. 
Remark on f. crassipes. This form differs pretty much in habit from typical 
Chorda jilum. It tapers rather imperceptibly towards the callus and on that account is, 
immediately above it, very much thicker that at the extremity and almost as thick 
as at the middle, while the thallus of the typical form is almost as much attenuated 
towards the base as towards the tip. Besides, it is smaller and of a lighter and clearer 
colour than common Ch. jilum. In inner structure, however, it accords very nearly with 
it. I have not observed any hairs in f. crassipes. Its being a deep-water form explains 
its lighter colour as well as the absence of hairs. 
Habitat. In the Arctic Sea proper this species is always sublitoral, in the Nor- 
wegian Polar Sea it is usually so; but it occurs here also in rock-pools within the 
litoral zone. Generally it lives at inconsiderable depths on gravelly bottom, particularly 
when the ground is composed of broken Lithothamnia, one to three fathoms below low- 
water mark. I have dredged f. crassipes in the lower part of the sublitoral region in 
15—20 fathoms. The present species is gregarious and flourishes both in exposed and 
