■Raeve.iïYLpi
P l a t e XLI. { A ) .
MYRIONEMA LECLANCHERII, Harv.
G en . C h a e . Minute Parasites, consisting of a mass of short, erect, simple,
jointed filaments, which spring from a th in expansion formed of decumbent,
cohering filaments, spreading in patches on th e surface of
other Algae. Spores oblong, affixed either to th e erect, or to the
decumbent filam e n t s . M y e io n em a {Grew.)— from ripios, a thousand,
and vqpa, a thread.
M y e io n em a Leclancherii; patches orbicular, th in , and with few vertical
filaments toward th e edges, convex with crowded filaments in th e
c en tre ; spores on long pedicels affixed to th e decumbent filaments,
obovate.
B iv tjla k ia Leclancherii, Chauv.—see. Lenorm. in litt.
H a d . On decaying fronds of M o d ym en ia probably commm.
Arninah Autumn. Torquay, Mrs. Criffiths. Down coast, M r. W.
n, 1835.
G e o g e . D i s t e . Shores of Europe.
D e s c e . Patches from a line to a quarter of an inch or rather more in diameter
orbicular, or slightly irregular in form, composed at first of decumbent
filaments radiating from a centre, and spreading on the surface oi the
Rhodymenia, closely cohering together into a thin membranous expansion,
wHeh is finely serrated at the edges. As the plant advances to ppfeetion,
vertical filaments, closely set together, spring in the centre of the patch,
where they fom an umbo, and gi'adually are developed outwards, becoming
shorter and shorter as they approach the edge Beyond this »«6c a wide
margin, destitute of vertical filaments or with a few scattered short ones
extends. Spores obovate, on long pedicels, or on the apices of abbreviated
filaments. At other times—and. indeed, more frequently--some of the
vertical filaments are found altered into lanceolate pod-hke bodies, represented
at fig. 4, jointed, but seemingly destitute of sporaceous matter.
Colour ohve brown.
In Autnmn the fronds of the common Dulse {Bliodymenia palmata)
in passing to decay are commonly found covered with
roundish olive spots, which, by a hasty observer may be overlooked
as being nothing more than incipient mortification. By
placing a small portion of such a spotted frond under the microscope,
the beautiful parasite here figured is brought to light. It
was first pointed out to me by Mrs. Griffiths m 1845, who found
it very plentifully at Meadfoot, near Torquay, and who received
specimens identical in every respect from M. Lenormand under
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