“ I t spreads over the diy naked earth. Stratum several
feet in extent, firm, coriaceous, of a glossy black colour, void
of lubricity. Filaments about half a line in length, twisted
like a corkscrew, radiating in all du-ectious.” — Carm.
When di’ied, the filaments lose their regularly spiral
character.
3. Spirillum minutissimum Ilass.
Plate L X X V . Fig. 8.
Char. Filaments excessively small, describing usuallg about
three turns.
Ilab. Ire lan d : Mr. Moore.
This exceedingly minute species I received from Mr. Moore.
The spiral character of the filaments is retained in drying,
ivhich is not the case in the previous species. I was much surprised
to notice, when examining a portion of a specimen
which had been preserved for a considerable time, th a t the
filaments were in lively movement, turning round and round
repeatedly, and ivith exceeding rapidity.
4. Spirillum T hompsoni Hass.
Plate L X X V . Fig. 7.
Char. Threads rather large, moniliform. Globules o f equal
size throughout their entire length.
Anahaina ? spiralis Thompson, Annals of Nat. Hist. vol. v.
Hab. Ballydrain Lake, near Belfast: Mr. Thompson.
“ The specimens obtained were invariably of similar
breadth, and rarely presented more than four spiral turns, and
Avhen of this size ivere one fiftieth of an inch in length. The
species at first, when mingling with the water, is of a dark
green colour; when in calm iveather it ascends to the surface
in separate particles, it appears pale g re e n ; when it does so
en masse (the earliest symptom of decay), it is of a pale blue ;
and in the last stage of decomposition, ferruginous. Having
on the 27th September brought home in several phials specimens
of what I had presumed to be this plant in all its
stages (i. e. from its first to its last appearance as a colouring
matter), I was much pleased to have the conjecture verified
hy microscopical examination. A portion taken from the
surface when it appeared pale green was, under the microscope,
of as dark a hue as in Ju ly , ivhilst the blue and ferruginous
colours exhibited different stages of decomposition.
When in the most perfect state in which the plant has
occurred to me, the globules appear entirely filled with
granules ; but when very highly magnified are each found to
be surrounded by a hyaline membrane. The blue and ferruginous
tufts exhibited generally its empty globules and the
escaped granules scattered all about; but the former were
seen in every state from full to empty ; some had granules
only in the centre, others were half full, and some separate
globules were entirely filled with the granular mass.
“ When two of the spiral portions come in contact, they
have an elastic power, by which they can, though slowly,
disentangle themselves and separate from each other, a fact
which I witnessed In various instances ; hut under such circumstance
only did I ever perceive any motion in this Alga.”
“ In some respects the Andb. spiralis resembles the Anab.
imjmlpabilis Bory, as described in the “ Encyclopédie Méthodique
; ” but its dull green unlustrous hue on paper is quite
opposed to that of the species ju st named, ivhich is described—
Préparée sur le papier, où on a facilité son développement,
elle est de la teinte la plus brillante, tirant sur celle de l’oxide
du cuivre, et luisant comme si on l’eut enduite d’eau de
gomme.” Besides, were this species of the exact spiral form
of that under consideration, this character would not I conceive
have been unnoticed in the description.” — Thompson.
33. A PH A N IZOM EN O N Morren.
Char. “ Filaments simple, cylindrical, flexile, membranaceous, '
glossy, articulated, cohering together in f la t lamellcE, lance-
olated at the apex, straight, or here and there infiated, fu l l
o f green matter, oscillating spontaneously, falling into
pieces.” — Morren.