T L u te -C e C J Y Æ .
P l a t e CCCXVIII.
MESOGLOIA GRILLITHSIANA, Grev.
G e n . C h a r . Frond f il if o rm , m u c h b r a n c h e d , g e l a t i n o u s ; t h e a x is c o m p
o s e d o f l o n g i t u d i n a l , s u b s im p l e , i n t e r l a c i n g f ib r e s , i n v e s t e d w i t h
g e l a t i n e ; t h e p e r i p h e r y f o rm e d o f r a d i a t i n g , d i c h o t o m o u s , c o lo u r e d
f l l a m e n t s . Fructification-, o v a t e o r e l l i p t i c a l , o l iv a c e o u s s p o r e s , a t t
a c h e d t o t h e f l l a m e n t s o f t h e p e r i p h e r y . . M b s o g l o ia {A g ),— f r o m
yiiEo-ot, the middle, a n d yXows, viscid; f r o m t h e g e l a t i n o u s a x is .
M esogloia Griffithsiana ; frond slender, equal throughout ; branches
alternate or irregular, filiform, long, simple, nearly bare of ramuli.
Mesogloia Griffithsiana, Grev. MS. Hook. Br. FI. vol. ii. p. 387. Wyatt,
Alg. Banm. no. 48. Harv. Man. ed. 3. p. 47. Kütz. Sp. Alg. p. 545.
U ab. In rock-pools between tide-marks, rare. Annual. Summer.
Livermead, Torbay, Mrs. Griffiths. Sidmouth, Miss Cutler. Eouiid-
stone, Mr. M'Calla.
Geogr. D is t r . Atlantic shores of Europe.
Desc r. Root a small disc. Fronds growing in tufts, filiform, about a line in
diameter, and from twelve to eighteen inches in length, with a percurrent,
undivided stem, set throughout with long, spreading, slender branches,
which are mostly simple and often naked, or having a very few spreading
or divaricating branchlets scattered at iiTCgular intervals. When the plant
is in a growing state it is clothed with colourless, horizontal fibres, spreading
from every portion of the stem and branches, and making them look,
when seen under water, of much greater diameter than they really are.
In age the axis decays, and the branches become hollow. The filaments
of the periphery are closely set, club-shaped, and beautifully beaded. The
spores are obovate, and raised in short pedicels. Colour a rather pale
olive-green, becoming greener in fresh water. Substance gelatinous, fiaccid,
slippery. In drying, the frond shrinks considerably, and adheres closely
to paper.
This species bears a striking resemblance in its ramification to
Ghordaria flagelliformis, but is always of a much paler colour,
and the microscopic structure very different ; the axis being
much less dense, and the substance more gelatinous and tender.
Still there is a considerable similarity in structure, and evidently
an affinity, through this species, between the two genera.
M. Griffithsiana worthily bears the name of its discoverer, so
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