t ' b/ f [ 2485 ]
GYROPHORA arctica.
Arctic Gyrophora.
CRYPTOGAMIA Alga.
» Gen. Char. Tubercles sessile,on a peltate frond,black,
with a plaited contorted disk, in whose clefts the
seeds are lodged.
Spec. Char. Frond coriaceous, rigid, thick, wavy
and folded ; upper side with tortuous plaits and
elevated points, ash-coloured ; under very smooth,
paler. Tubercles at length globose, copiously
plaited.
Syn. Gyrophora arctica. ' Ach. Meth. 106. t. 2. f . 6.
T h is is here admitted as a British species, on the authority
of a specimen, the uppermost in our plate, obtained by Mr.
Turner from the herbarium of the late Mr. Hudson, who probably
collected it in Devonshire. The other was sent by Dr.
Wahlenberg from Norway, and leaves no doubt as to the identity
erf the species, though its under side displays none of that yellowish
white hue mentioned by Acharius.
Wahlenberg himself doubts whether this Gyrophora be really
distinct from proloscidea; see t. 2484, though he allows its
appearance to be altogether different. The substance of the
frond is more thick, rigid, and tenacious ; the upper surface more
obtusely corrugated, and besprinkled with warts. By age it
becomes entirely black above, and still more unequally rugged,
with reflexed edges. It varies from an inch and half, to two
inches, or more, in diameter. The tubercles become elevated
when old. They are abundant, and formed of numerous contorted
plaits. We. are most inclined to believe this one species with
G. cylindrica and. proloscidea, some German specimens of which
in our possession seeming to come very near what is above
described.