Spongomorpha duriuscula var. cartilaginea (Rupr.) Yamada

Sporjbmorpha duriuscula Collins, var.
cartilaginea comb, nov. Yamada, Sci. Pap.
Inst. Algol. Res, 1: 10. Mr 1935.

S. duriuscula Collins var. cartilaginea comb. nov.

Syn. Conferva cartilaginea Ruprecht, Tange Ochot. Meeres (1851), p.

357.

Syn. Cladophora alasJcana Collins, in Collins, Holden and Setchell,
Phyc. Bor.-Amer. (Exsicc.), no. 917 (nomen nudum).

Japanese name. Kata-moturegusa.

. » Hab. Iema.

& All our specimens answer well to the original description of Sp. car-
^Ltilaginea Rupr. In those specimens the cell membrane is very thick and
cartilaginous, becoming very hard to the touch in drying. The diameter
of the cells is about 120ju near the base of the frond, and about 325/« in

Marine Algae from Urup, the Middle Kuriles

11

the upper parts of the branches. Having examined the type specimens,
Yendo* amalgamated Conferva duriuscula Rupr. and C. cartilaginea Rupr.
into one species, calling it Acrosiphonia duriuscula (Rupr.) Yendo. Our
specimens are about the same as Yendo’s, which were collected in Onne-
kotan, the Kuriles, and identified as Conferva cartilaginea Rupr. Tokida,**
on the other hand, reported Spongomorpha duriuscula Collins from
Robben Island. Thanks to his kindness, I have examined his dried speci-
mens as well as those preserved in formalin and found that they answered
fairly well to the description of Conferva duriuscula Rupr. In those speci-
mens the cell membrane is not so cartilaginous as in our Urup specimens,
it being rather easy, therefore, to distinguish one from the other, especially
in the dried state. Consequently it seems to me that we must separate our
cartilaginous plant from the typical S. duriuscula, at least, as a variety.

ctZ'uL,

S. duriuscula Collins var. tenuis var. nov. ?. // y a Tr, ? q v
Frons tenuior quam in typo.

Japanese name. Hoso-moturegusa.

Hab. Iema.

In our specimens the diameter of the cells is 90-110 [i near the base
of the frond, and 170-200jx near the tips of the branches. The cell mem-
brane near the base of the frond as well as in the rhizoid shows very fine
horizontal striations.

This variety grows sometimes on rocks in the littoral belt, sometimes
on the frond of Thalassiophyllum Clathrus Rupr.

/r\ a

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