ing the generic character, would ever think of looking for it among
them. Agardh speaks of very short filaments descending from the
vesicle, green in their upper part, but colourless below. The vesicle
or receptacle certainly possesses a very short neck, which divides into
two or three main branches, and the branches into fine fibres, but in
no part resembling the filaments of the Vaucherioe, any more than does
the receptacle itself resemble the vesicles of those plants. I regret
that I can offer nothing respecting this curious plant, beyond what is
already known, having failed in my attempts to procure fresh specimens
to examine, for this work, and no satisfactory analyses can be
made fi-om dried ones.
There is also another plant arranged doubtfully with the Vaucherioe
by Agardh, and unhesitatingly by Lyngbye and Sprengel. I allude to
the Conferva mullicapsularis of Dillwyn. According to Dillwyn, the
frond is decidedly jointed : and the vesicles, as he has represented
them, especially in his Supplement (tab. D. f. 4.) contain a number of
distinct granules, similar to those which occur in Monema, Sckizo-
nema, &c.
I. B o t r y d iu m g r a n u l a t u m . Tab. XIX.
Botrydium argillaceum, W a l l r . A n n . B o t. p . 153.
Hydrogastrum g ranulatwn, D e s v . F L A n g . p . 19.
Vaucheria granulata, L y n g b . H y d r o p h . D a n . p . 78.
Vaucheria radicata, A g . S p . A lg . v . 1. p . 465. S y s t. A lg . p . 173.
Coccochloris radicata, S p r e n g . S p . P L v . 4. p . 372.
Tremella granulata, H u d s . F L A n g l. p . 566. S m . E n g . B o t. t . 324.
Viva granulata, L in n . S p . P L v . 2 . p . 1633. L ig h t f . F L S c o t. p . 976.
H a b . On damp clayey ground, dried up ditches and ponds, shady
paths in gardens, &c. Annual. Spring and autumn. At Camberwell,
on the mud of ditches and ponds, “ English Botany.” On
the perpendicular banks of rivers and lochs in shady places, not unfrequent,
Lighfoot. On borders and pathways in the Botanic Garden,
Glasgow, Hooker.
Plant about the size of a large pin’s head, sessile upon the surface of
the ground, covering a lai-ge space in a densely crowded manner, composed
of a hollow spherical vesicle or receptacle, not homogeneous as
in the genus Vaucheria, but filled with a watery fluid, which escapes
by an irregular terminal orifice. The receptacles at length collapse,
become cup-shaped, and then cover the ground with a thin greenish
crust, like that of some Lichens. At its under part, each receptacle
i
is terminated by a very short neck, which divides into a radicating
tuft of pale fibres. Substance fragile and membranaceous. Colour a
pale green.
The fructification of this plant is unknown. Does the watery fluid
contain it ? The structure of the receptacle seems to be minutely
granular. By Lightfoot it is said to grow sometimes as large as peas.
Those I have met with myself rarely exceeded the size of mustard-
seed.
ADDITIONS AND CORRECTIONS.
Page 52. Punctaria latifolia. Since the description of this plant was
printed, I have been indebted to Mrs Griffiths for more perfectly
developed specimens, gathered by herself, at Torquay. Some of
them are nearly three inches wide. The surface is covered with a
minute and almost invisible fringe of colourless articulated filaments,
about a line in length. The substance of these specimens, Mrs
Griffiths describes as thick and gelatinous.
P. 70. Polyides rotundus. Some individuals of this species have
been detected by Mrs Griffiths at Sidmouth, having the extremities
of the frond somewhat thickened, and containing roundish dark
coloured scattered granules imbedded in the surface. In such plants
the ordinary spongy fructification is absent.
P. 88. Rhodomenia polycarpa. Under the description of this plant
I have hazarded a query, whether it has any relation with the Fucus
Sarniensis of Mertens, and stated Mr Arnett’s opinion in favour of
the question. Since that portion of my work was printed, I have
procured a copy of the Catalecta Botanica, and have received an
authentic specimen of Fucus Sarniensis, the handwi-iting of Professor
Mertens being attached to it. I am thus enabled to say, that
my plant is perfectly distinct from Fucus Sarniensis, which is really
only a variety of Rhodomenia palmata, producing even the cloudlike
sori of ternate granules belonging to that alga.
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