regarded as generally distinct therefrom, as D. cylindricum
and D. Swartzii have to be so considered.*
52. G L iE O P R IU M Berk. M S S .
Char. Filaments cylindrical, invested in a broad elastic sheath.
Cells slightly crenate. Endochrome stellate.
From the above definition it would appear th a t this genus
does not differ in any marked manner from Desmidium
There is certainly more ground for its formation than for the
establishment of Kiitzlng’s Didymoprium ; but perhaps the
ends of science and of nomenclature would have been answered
to have placed the two species which it is made to
comprise and which differ as widely from each other as they
do almost from the genus Desmidium in a distinct section of
that genus.
1. C lasoprium d is s il ien s Berk.
Plate L X X X I I I . Figs. 3, 4.
Char. Filaments fragile. Cells slightly crenate, grooved between
the crenatures, nearly as long as broad. Sheath
broad. Endochrome six or seven rayed,
Desmidium mucosum Breb. Conf. dissiliens, Eng. Bot.
t. 2464. D. mucosum Kalfs, in Annals, vol. xi. p. 374.
plate viii. fig. 2. Glwoprium dissiliens Jenner, in Fl.
Tunbridge Wells, p. 192.
Hab. Crom Byc lan: W. Borrer, Esq. Tunbridge Wells
and other places in Sussex, freq u en t: Mr. Jenner. Near
Bedgelert and about Dolgelly, North W a le s; Swansea,
South Wales; plentiful near Penzance, Cornwall: Mr.
Ralfs. High Beech, Essex; Hertford Heath and
* Mr. Jenner has pointed out a character which seems to set the question
of the distinctness of this species at rest. He states that in Desmidium
quadrwigulatum the angles of the cells are rounded, while in D . Swartzii
they are acute.
Wormley West End, H e rts: A. H. H. Bandon: Prof.
G. J. Allman. Co. Kerry : Mr. Andrews.
The filaments when viewed separately, or as regards the
line of cells are rather slender, b u t when taken in connection
with the broad sheaths, their diameter is considerable ;
this sheath, though expanded and firm, often, unless a good
microscope be used, escapes detection. I t is from the presence
of this sheath that the plant owes its excessive mucosity,
and it is by it th a t we account for the parallel arrangement
which the filaments frequently assume on the field of
the microscope, without at the same time appearing to touch
each other, although they really do so by means of the almost
invisible mucous sheath. The contrast between the coloured
cells and the transparent sheath renders this an exceedingly
beautiful microscopic object.
2. G laiopkium mucosum Berk.
P late L X X X I I I . Figs. 5, 6.
Char. Filaments not fragile. Cells usually nearly as long
as hroad, not grooved round the centre. Angles o f cells
mostly minutely bicrenate. Sheath very broad, fa in t.
Conf. mucosa Mertens, Dillw. Syn. t. /3; Harvey, in
Hook. Br. Fl. p. 351.; also in Manual, p. 127. Glwo-
prium mucosum Jenner, in Flora of Tunbridge Wells.
Desmidium bimucronatum Hassall, MSS.
Hab. In stagnant w ater, B a n try : Miss Hutchins. A p p in :
Captain Carmichael. Cheshunt Common, High Beech
and elsewhere: A . H. H. Penzance: Mr. Ralfs. Bogs
at F isher’s Castle, very abundant, Sept. 1844; Chiltington
Common: Mr. Jenner.
This species differs very considerably from the previous one,
in having somewhat longer cells, a more highly developed
mucous sheath, in the absence of the central constriction of
the cells, and in the presence of the excessively minute bicrenate
processes placed at the angles of the cells, and which were