32 
K. MI V AUE 
Harvey recognized as the characteristic of the Japanese variety, 
they are not uncommonly present even in the American specimens.* 0 
Consequently our Hokkaido plant is not worth recognizing as a 
variety. 
5. Alaria Greviij.e 
GREVILLE, Algae Briatannicae, Synopsis, p. xxxix and p. 25, 1830. 
The upper portion of the stipe is flattened, and along its two 
sides numerous leaflets stand oppositely side by side. The lower 
leaflets are older in growth. They are shed successively from the 
undermost to the upper ones. New leaflets sprout at the upper- 
most place above those already existing. Sporangial sori are formed 
on both surfaces of these leaflets, hence they are called sporophylls. 
The flattened part of the stipe from which the sporophylls arise 
is called the rhachis. The blade is terminal, entire, with a longi- 
tudinal percurrent midrib located at the center, usually provided 
with cryptostomata, and destitute of mucilage ducts. 
The genus Alaria is known at present to comprise twenty-two 
species, of which many are distributed in the Arctic Ocean and 
the North Pacific; five occur in the vicinity of Japan. 
1. Alaria fistulosa Posters et Ruprecht 
(Plate 21) 
Postels et Ruprecht. Illustrationes Algarum, p. 11, Tab. XVI, 1840. 
Illustration. Postels and Ruprecht, loc. cit., Tab. XVI, 1840. 
Japanese name . Oni-wakame. 
Kerupu (among hunters of marine mammals in the Kuriles), 
Kairoppa or Kairoppu (among the natives of the Kuriles), Karafuto- 
wakame (Kitami Province). 
Holdfast composed of filiform hapteres branching several times, 
complicated, forming a turbinate compact mass of very hard quality. 
Stipe somewhat complanated, solid, bearing numerous, crowded, 
obovate or oblong sporophylls. Sporophylls shortly petiolate, com- 
pletely covered by the sporangial sori excepting only a narrow 
margin, 9-10.5 cm in length, 2-3 cm in width. Blade very long, 
claimed by someone to be sometimes up to 40-50 fathoms in length, 
32) In the diagnosis of the genus Costaria given by SETCHELL and GARDNER 
(1925, p. 609) it is stated that “blade •not rarely perforate.” 
