10 
K. MI Y ABE 
with Laminaria ochotensis is identical specifically with the latter, 
showing no difference in the internal structures. As for the charac- 
teristic very narrow blade of this plant, it is no doubt due to the 
suppression of normal growth induced by the overpopulation of the 
fronds crowded on a single mass of holdfasts. 
The present species resembles most closely Laminaria cuneifolia, 
which occurs along the northern coasts of Europe, in the eastern 
part of the Siberian Sea and in the vicinity of Behring Strait. 
According to the views of Agardii and Kjeij.man, Laminaria sac- 
charina var. cuneifolia mentioned by Ruprecht in his Tange des 
Ochotskischen Meeres, p. 351, is probably identical with the species 
alluded to above. However, Rupreciit’s description is very simple, 
only mentioning the cuneate base of the blade, the shortness of 
the stipe, the presence or absence of the marginal undulations, 
and no more, so that it is impossible without seeing the specimens 
to decide whether the plant from the Ochotsk Sea is referable to 
Laminaria cuneifolia as Agardii believes or it is identical with our 
L. ochotensis. 
A description of Laminaria cuneifolia will be given here for 
reference. 
Holdfast consists of filiform hapteres branching several times. 
Stipe is short, solid, and somewhat cylindrical in shape. Blade is 
membranous, elongato-elliptical linear in shape, undulating or not 
on the marginal portions, and provided with a row of bullations 
along both sides of the median fascia. Sporangial sori develop 
first as large spots on the median fascia in the lower portion of 
the blade. The base of the blade is cuneate, sometimes cordate 
when matured. Mucilage canals are present in both blade and 
stipe. Blade has light yellowish tint. As compared with this 
Arctic species, the present Hokkaido plant is characterized by 
having a thick, coriaceous blade, which is linear oblanceolate or 
linear spindle in shape. It has no bullations, at least when grown 
up to a certain extent, though it is not clear whether a very young 
blade has bullations along the median fascia or not. The plant is 
blackish-brown in color being rich in pigments. It is distributed 
in Hokkaido only along the coasts washed by a distal reach of a 
warm current, but never along those washed solely by a cold cur- 
rent. So it cannot be considered identical with Laminaria cuneifolia 
which occurs along the coasts of Siberia and in Behring Sea. Hence 
