134 KJELLMAN, THE ALGA OF THE ARCTIC SEA. 
Delesseria angustissima (Turn.) Grier. 
in Harv. Phyc. Brit. t. 83. Fucus alatus y angustissimus Turn. Hist. Fuc. 3, p. 60. 
Descr. Delesseria angustissima J. G. AG. Spec. Alg. 2, p. 686. 
Fig. » » Harv. Phye; Brit, 1. ¢ 
Syn. Delesseria alata var. angustissima Kunen, Nordl. Alg. p. 14. 
Remark on the determination of the species. 1 have never seen any specimens of 
this alga from the Polar Sea collected by others, nor have I ever met with it there 
myself. It is only on the authority of Krenn that I give it «a place in the present 
work. KirEn’s collections contain no specimens of this species, but in his list of the 
alg of Nordlanden he declares decidedly that D. angustissima Harv. Phyc. Brit. pl. 
83 was found there common. I have no reason to suppose that Kiern’s statement 
should not be founded on accurate comparisons, and the alga growing at Scotland and 
the Orkney isles, its occurrence at Nordlanden is highly probable. 
Habitat. It is litoral, attached to stones beneath Mucacew. 
Geogr. Distrib. It is known only from the Atlantic region of the Polar Sea, in 
the southern part of which region it is commonly spread, according to KLEEN. 
Locality: the Norwegian Polar Sea: Nordlanden common and _ plentiful. 
Delesseria alata (Hups.) Lamour. 
Hiss. p. 124. Fucus alatus Hups. Fl. Angl. p. 578. 
Descr. Delesseria alata J. G. Ag. Epiecr. p. 483. 
ig. » » Harv. Phye. Brit. t. 247. 
Kesice, » »  Aruscu. Alg. Scand. exsice. N:o 75. 
Syn. Delesseria alata Arescu, Phye. Seand. p. 292. 
» »  KueeEn, Nordl. Alg. p. 14. 
Fucus alatus Gunn. Fl. Norv. 2, p. 91. 
» » We. Fl. Lapp. p. 492. 
flabitat. In the southern part of the Norwegian Polar Sea at Nordlanden this 
species grows partly in rock-pools between tide-marks, partly within the upper part of 
the sublitoral zone, attached to stones or more usually to Laminariacew. Farther north- 
wards on the coast of Finmarken it always keeps, according to my experience, in the 
litoral region, forming in exposed localities, together with Ptilota elegans, a dense mat 
on the steep, flat or somewhat hollow, outsides of stones or rocks covered by masses 
of Ozothallia ,and other Fucacew. Here it is dwarfed, seldom, if ever, reaching more 
than 3—5 cm. in height by 1—2 mm. in width, while even at Nordlanden it becomes 
over 8 cm. long and about 4 mm. broad. The specimens from Nordlanden found in 
KLEEN’S collections are all sterile, nor does he mention in his treatise on the marine 
Flora of Nordlanden that he has ever seen any specimen with any kind of propagative 
organs. Myself found only sterile individuals at Finmarken. On the west coast of 
Sweden the plant bears tetrasporangia during the winter months, December and January, 
and ArrscHouG states it to be »mensibus Martii atque Aprilis in mari Bahusiensi fruc- 
tificans». Accordingly, the plant here develops its organs of propagation in winter and 
spring. Probably it does so also farther to the north. 
