“ In no other Conferva is the nnmher of the filaments so considerable
as this. Their total diameter equals that of the largest horsehair. They
divide in every direction from a little disc, ramify to infinity, observing
remarkably well the dichotomous disposition in their first division, their
branches becoming subsequently vague. Their total length extends even
to four inclies.
“ From their origin even to their extremity these filaments are clothed
with microscopic branches, so impacted that the whorls are not apparent
in scarcely any iiirection ; with a simple lens they are not better discovered,
from which it might be supposed that one was observing a
Thorea. I t is but towards the points of the branches that, by the assistance
of a strong lens, they are at last distingnished. These whorls are
very closely approximated, horizontal, compressed the one upon the
other, and becoming so confused as to form around the filament, which
is green or yellow, and very flexible, a continuous down, mucous to the
touch, sometimes very pale, more frequently of a very agreeable bluish
watery g reen; this colour is, moreover, deep towards the point of the
branches. As it grows old the plant turns yellow, and is discoloured.”
Bory.
var. kera top hy tum . Bomj.
Beautifnl blue-green, tbin, very muob braucbed, diobotomous,
witb tlie black setaceous base naked, branches all equal, slender,
tbin, apex slightly incrassated, whorls distinct.
S iz e . Cellules clavate, about -03 x '015 mm.
Batrachosperma Iceratophyta, Bory Ann. Mus. xx., t. 31, f. 2.
Batrachospermum suevorum, Kutz. Spec. 536.
Habit, colour, and ramification of B. vagum, but with the whorls distinot.
Plate GXXV. fig. a, portion of filament X 30 j 6, portion X 200
diam.
B a tia ch o sp e im um atrum. Harv. Man. 119.
Violet-coloured wben moist, dark brown, almost black wben
dry, vaguely aud much braucbed, reaching 2 inohes, whorls
abbreviated, d is ta n t; interstitial branchlets very short, one or
two-celled.
S iz e . Cellules -012 mm. diam.
Jenner Tunb. Wells 176. Hass. Alg. 114, t. 16, f. 4.
Conferva atra, Dillw. Conf. t. 11. Hull Br. Fl. 332. Huds.
Ang. ii., 597. Eng. Bot. i., t. 690. With. Arr. iv., 134.
Gray. Arr. i., 380.
Batrachospermum detersum, Eng. Bot. ii., t. 2543.
Batrachospermum moniliforme, v. detersum, Eng. F l. v., 388.
Mack. Hib. 221.
Batrachospermum moniliforme, var. i. atrum, Eabh. Alg. Eur.
iii., 406. Kirch. Alg. Schles. 45.
Lemanea setacea, Bory Ami. de Mus. t. 23, f. 3.
In streams and ditches.
Flate CXXVI, fig. 1. a, portion of filament X 30 ; h, portion X 200
diami
“ The articulations, or internodes, may be compared to reversed cones,
the superior part or whorls being formed of a few short, simple subulate
filaments, which are not beaded ; in these filaments the colouring
matter chiefiy resides, and it is amongst them that the glomerules are
formed ; that portion of each articulation which is below the whorl is
transparent, and beautifully exhibits the tubular and jointed^structure
of the layers which invest the primary cells in all the species of tbe
genus Bati'achospermum ; from many of these tubes short branches are
given off, which have almost the appearance of scales.’’—Hassall.
var. D illex iii. Hovy. Ann. de i\Iiis. xx., t. 22, /. 2,
Filaments dark brown, very tbiu, lower nodes remote, tbe
interstices besot very densely witb prominent cells, upper nodes
crowded, brancblets very short, consisting of 3-4 cellules, extreme
apical nodes confluent.
S iz e . Cellules -012 mm. diam.
Lemanea Dillenii, Bory. Ann. de Mus. xx., 23.
Batrachospermum vagum, e. D illenii, Kabh. Alg. Eur. iii.,
407.
Conferva fo n ta n a nodosa, lubrica, nigris. Dill. Muse. t. 2, f.
46.
This is usually considered as a variety ot B. vagum, but it seems more
closely allied to B. atrum, if that be really a distinot speoies.
Plate C X X V I. jig. 2. Portion of filament X 200 diam.
Genus 120. THOREA. Bory. (1808.)
Thallus filamentose, attenuated at the apex, branched, purple-
brown, villose, mucous, witb a solid central medullary stratum,
surrounded by dichotomously divided branchlets.—S u r un genre
nouveau de la Cryptogamie aquatique, nommé Thorea.
Thozea ram osissim a. Bory Ann. Mus. xx. 127.
From a band’s-breadth to a foot long, and rarely two feet,
very much branched, about the thickness of a horsehair, dark-
green, of a beautiful purple-violet when dry,^ ramelli spreading
horizontally, long and short alternating, articulate, joints 1 - 8
times as long as broad, or twice th at length.
Harv. Man. 120. Hass. Alg. 65, t. 16, f. 3-4. Eabh. Alg.
Eur. iii.
Batrachospermum Juspidum, De Cand. F l. F r. ii., 60.
Attached to wood, &c. Walton-on-Thames.
Plate CXXVIl. fig. a. Small plant, natural size ; b, ramuli and spore j
C) portion of filament X 400.