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P late C C X X I.
RYTIPHLÆA THUYOIDLS, Harv.
G e n . Ch a e . Frond filiform or compressed, pinnate, transversely striate, reticulated
; the axis articulated, composed of a circle of large, tubular,
elongated ceRs {siphons), surrounding a central ceU; the periphery
of several rows of minute, irregular, coloured oeUules.
of two kinds, on distinct individuals ; 1, ovate capsuL
containing a tuft of pear-shaped spores ; 3, tetraspores, contained in
minute, lanceolate receptacles {stichidia) in a double row. R y t i p h læ a
{A g ),—from pvris, a wrinhle, and 0Xoior, the harh, because the surface
is transversely wrinkled or striate.
R y t ip h læ a thuyoides ; stems erect, rising from creeping fibres, terete ;
below simple and set with short, spine-like ramuli ; above much
branched; branches alternate, very erect, bi-pinnate; pinnæ multifid
or pinnulate ; axils rounded ; ceramidia ovate, sessile, densely set.
P o l y s ip h o n ia thuyoides, Harv. in Mack. M. H ii. part 3. p. 205. Wyatt,
Alg. Banm. no. 305. Harv. Man. p. 86. E. Bot. Suppl. t. 2882.
G e a m m it a rigidula, Bonnem.
H a b . In pools left by the tide, growing either on the rocky bottom or on
Corallines and other small Algæ. Perennial. Summer. Abundant
on the west coast of Ireland. Portrush, M r. Moore. Howth and
Balbriggan, Miss Gower. Ayrshire coast, M r. Thompson and Rev. B .
Landshorough. South coast of England, Devonshire, Mrs. Griffiths.
Mountsbay and Ilfracombe, M r. R a lfs. Jersey, Miss White.
G e o g e . D i s t e . Atlantic shores of Europe.
D e s o e . Boot, a widely spreading mass of creeping fibres. E rm is from three to
six inches high, twice as thick as hog’s bristle, forming wide, but not very
crowded tufts. Stems very variable in division : in some specimens nearly
simple, with three or four long, rod-like branches, set with very short pinnulate
ramuli ; in others naked at the base, but closely and regularly pinnated
or bipinnated from the middle upwards, the pinnæ long and vhgate,
closely pinnulate. Other specimens are excessively bushy, the branches
springing from the upper part of the stem in a very irregular manner. In
all varieties the branches ai-e remarkably erect, and generally straight, and
more or less regularly pinnate or bipinnate. Bamuli below simple and subulate,
above pinnulate and forked, one or two lines long. The whole frond
is marked with transverse striæ at distances about equal to the diameter,
and the surface is reticulated with anastomosing cells. Eructijkaiion ;
ceramidia oblong-ovate, densely crowded on the ramuli, sessüe, containing
a tuft of pear-shaped spores. Tetraspores in distorted ramuli. Substance
somewhat rigid, between cartilaginous and membranaceous. Colour, a fine
dark brownish purple, becoming more or less tinted with olive when exposed
to sunlight.
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