and length of the cells vary considerably, according to the
age of the plant.
3. L y n g b y a co pulata Hass.
Plate L X X I I . Fig. 14.
Char. Filaments very flexible, o f about the same diameter
as those o f L . muralis, adherent to each other fo r a considerable
portion o f their length. Cells short.
L . muralis var. copulata Carm. MS.
Hab. Appin ; Captain Carmichael.
This is a very curious production, exhibiting some relation
in the adherence of the filaments the one to the other to
Calothrix mirabilis —■ than Avhich it is not less wonderful.
I t is very rare.
4 . L y n g b y a v ir e s c e n s Hass.
Plate L X . Fig. 3.
Char. Filaments o f about the same diameter as those o f L .
punctalis. Cells usually somewhat beaded, rather longer
than broad. Fndochrome not quite filling their cavities.
Hab. On stones, in a pond, near Wanstead Flats, Fssex:
A . H. H. Penzance: Mr. Ralfs.
This species, except in the simplicity of its filaments, bears
a very close resemblance to the Draparnaldice. Like the
species of that genus, it is of a beautiful green colour, fragile,
slippery to the touch, and delighting in pure and slowly running
waters. The filaments are always attached, in which
respect it agrees with L . zonata.
5. L y n g b y a T h o m p s o n i Hass.
Char. Filaments attached, exceedingly slender. Cells once or
twice as long as broad.
Meloseira Thompsoni Harv. in Manual, p. 195.
Hah. Growing on stones in a mountain rivulet at Bal-
lantrae, Ayrshire: Mr. W. Thompson.
This is clearly a Lyngbya, and the most minute species of
the genus with which I am acquainted. I t is described as
forming “ beautiful, glossy, dark green tufts.”
6. L y n g b y a pl o c c o sa Hass.
Plate L X . Figs. 1, 2.
Char. Filaments o f smaller diameter than those o f L . muralis.
Cells at fir s t cylindrical, subsequently beaded, rather longer
than hroad.
Conf. fioccosa Ag. Conf. fugacissima Dillw. Supp., t. B.
C. fioccosa Harv. Manual, p. 126.
This species is very distinct and abundant, being found
in great quantities in almost all ponds, on heaths and bogs.
The filaments are rarely attached, are highly mucous and
tenacious. When kept in water it does not quickly pass to
decay. Specimens are often met with, which when placed
under the microscope appear quite colourless, the endochrome
having escaped from the cells.
7 . L y n g b y a p u n c t a l i s Hass.
P late L X . Fig. 4.
Char. Filaments o f less diameter than those o f Lynghya
fioccosa, very mucous. Cells two or two and a h a lf times
as long as hroad, slightly contracted. Fndochrome at
fir s t quadrangular, not filling the entire cavity o f the cell,
arranged usually in two separate masses, but sometimes
there is but one ; subsequently the cells becoming inflated,
the endochrome assumes a spherical form.
Sphoeroplea punctalis Berk. Glean. Alg. t. 3. fig. 2. Conf.
punctalis Dillw. t. 51. Sph. punctalis Harv. in Manual,
p. 144.