with an indefinite numher of branches ; branches inconstant in their
length, the lower ones one to three inches, naked towards their insertion,
spreading horizontally, pinnated in distichous manner, the pinnæ
mostly opposite, approximated, and often set with one or even two
series of pinnulæ, each shorter than the preceding one. Substance
membranaceous, somewhat gelatinous, very tender and delicate. Colour
a bright grass-green. In drying the fluid green colouring matter colapses
irregularly, and generally leaves the stem and branches pellucid.
It adheres closely to paper, and shines as if varnished.
The young and simpler forms of this elegant plant resemble a feather,
and in the more branched individuals, each branch suggests the
same idea, the naked portion serving to represent the quill. The frond
is singularly weak and flaccid. I do not possess any authentic specimen
of Bryopsis composita, but having individuals of B. plumosa answering
to the description of that species in the ramification of the
frond, I cannot perceive any chai-acter by which they can be kept
apart,
2 . B r y o p s is h y p n o id e s .
Frond slender very much branched, the branches long, the ramuli
capillary irregularly inserted somewhat erect, the lower ones elongated.
Bryopsis Arbuscula, A g . S p . A lg . v . 1. p . 451. S y s t. A lg . p . 179.
H a b . On rocks and stones in the sea. Annual. Summer and
autumn. At Southerness (or Saturness), in the county of Kircud-
teght. Sir William .Jardine Bart. Prestonpans, in the Frith of Forth,
Dr HaselL
Frond two to four inches long, very slender, cylindrical, branched
m a lax bushy manner, the branches very fine, elongated, bearing one
or two senes of somewhat erect capillary scattered ramuli, arising
without regularity, and in a scattered manner, the lower ones elongated
Substance tender, confervoid, and somewhat gelatinous. Colour a bright
pale ^-een. In drying, it adheres closely to paper, and shines as if
varnished.
Although I have thought it right to give this plant a distinct place,
am not by any means convinced that it is not a variety of the preceding
species. The habit is certainly different, and the ramuli are more
■'4
or less erect, and irregular in their insertion. I have, however, observed
a want of uniformity more than once in the pinnulæ of B. plumosa,
especially in large specimens, and the other characters may not
he constant.
G e n u s L III. VAUCHERIA, De Cand. Tab. X IX .
G e n . C h a r . Fronds aggregated, tubular, continuous capillary,
coloured by an internal green pulverulent mass.
Fructification, dark green homogeneous vesicles (coniocystæ,
Ag.) attached to the frond.
O bs. This most natural and well defined genus, was originally proposed
by M. Vaucher, of Geneva, under the name of Ectosperma, in
an excellent work, entitled “ Histoire des Conferves d’eau douce.”
De Candolle, however, in compliment to the acumen of M. Vaucher,
and with a view to perpetuate his name, denominated it Vaucheria.
This arrangement has been universally admitted, except by M.
Bory de St Vincent, who protests against the change. “ Nulle bonne
raison,” he observes, “ n’autorisant cette mutation qu’adoptèrent les botanistes
peu versés dans fhydrophytologie, (!) nous avons cru la devoir
regarder comme non avenue dans notre Dictionnaire Classique d’Histoire
Naturelle ; et respectant une antériorité injustement méconnue,
nous avons réservé le nom de M. Vaucher pour désigner un autre
genre de lui, qu’il avait fort bien établi, mais assez mal à propos appelé
Proliféra, désignation qui pèche contre les règles de la nomenclature.”
The stmcture of the frond of Vaucheria is exactly similar to that
of Bryopsis, and of the tubular filaments which compose the frond of
Codium. Its precise nature, however, is not obvious, there being no
traces either of cells or reticulations. The habit is that of the Confer-
vcB : some float in masses in the water, others form an interwoven stratum
on the surface of damp ground, the edge of waterfalls, or beneath
the gentle trickling of springs. Many are branched in a dichotomous
manner, others irregularly. The fructification, which is either terminal
or lateral, is generally more or less spherical, and seems to consist
only of a little case or vesicle, filled with a dense dark green pulverulent
mass. 'When mature, it is deciduous, and the development of
9 j;