KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:o 5. 267 
length of 30 cm. In the interior of Altenfjord it was in general low but bushy. Though 
being often pretty gregarious, it occupies only inconsiderable spaces. In August and 
September it is richly provided with zoosporangia on the north coast of Norway. 
Geogr. Distrib. Known only from the Atlantic region of the Polar Sea, at several 
places abundant. The most northern point where it has been taken is Gjesver about 
Kate Noe. 
Localities: The Norwegian Polar Sea: Finmarken at Gjesver, Talvik, and Sver- 
holt, at the two first-named places rather abundant, but local. 
Gen. Dictyosiphon (Grev.) ARESCH. 
Bot. Not. 1873, p. 164; Grev. Alg. Brit. p. 55; char. mut. 
Dictyosiphon corymbosus nob. 
L. fronde fusco-flavescente, solido; axi primario distincto, ramis subcorymbosis, elongatis, simplicibus vel 
parce ramulosis; zoosporangiis spe confertis, a superficie thalli visis vulgo ellipsoideis. 
f. abbreviata nob. 
f. ramis vix semipedalibus, crassitudinem seta excedentibus. 
Tab. 26, fig. 12—15. 
f. elongata nob. 
f. ramis usque ultra pedalibus quam in precedente tenuioribus. 
Syn. Dictyosiphon hippuroides KsettmM. Algenv. Murm. Meer. p. 46; ex parte. 
Description. This alga is attached by a callus and the frond becomes from half 
a foot (f. abbreviata) to more than one foot (f. elongata) long. It resembles D. fani- 
culaceus in colour and by its branching reminds one much of Codlonema chordaria f. 
bahusiensis. The main axis is distinct and beset in its whole length with rather nu- 
merous secondary axes of the first order, from half a foot to one foot long, usually 
unbranched, sometimes bearing one or two branches of the second order. Branches of 
a higher order than the second are rare. The secondary axes of the first order are 
almost corymbose. The principal axis is markedly attenuated towards the base, the 
secondary axes not at all or exceedingly little, by which marks the present species is 
distinguished in habit from species of Coilonema. The branches taper perceptibly to- 
wards the tip, more in f. elongata, less in f. abbreviata. With regard to structure 
this species is most nearly allied to D. hippuroides. The cortical layer is composed 
of small angular cells which in optical longitudinal section are squarish or irregularly 
four-sided, in the lower part of the frond rectangular. The latter are arranged in 
rather regular, longitudinal rows. The endochrome of the cortical cells is less plentiful 
and lighter in colour than in D. hippuroides. The thick central layer is composed of 
elongated cells of varying width with comparatively thin walls. In full-grown individuals 
there is to be found in the centre of the frond a small number of fine cell-rows 
resembling those of D. hippuroides; fig. 13. Hairs are rarely found. The zoosporangia 
