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D E SM ID IUM c y l i n d r i c u m .
Cylindrical Desmidium.
C l a s s a n d O h d e i i CRYPTOGAMIA ALGAS, £ i ,m . _ N A T . O r d . ALGJE, J uss.
G E N E R IC C H A R A C T E R .
F ila Simplicia, a rticú la la , a n g u la ta , a n g u lis h ya lin is, crenatis, a rticu lis demum
secedentibus.
Filaments simple, jointed, angular, the angles hyaline, crenate; joints at
length separating.
S P E C I F IC c h a r a c t e r .
Desmidium cylindricum; f i l i s c y lin d ric is, b ia n g u la tis, a n g u lis bicrenalis.
D. filaments cylindrical, two-angled, angles 2-crenate.
Conferva dissiliens, Sm. Fngl. Bot. t. 2464.}
H ad. A t the bottom of shallow pools and ditches of fresh-water in spring.
Appin, Captain Carmichael.
Plant forming a thin, fine green gelatinous fleece, like the preceding species.
Filaments an inch or more in length, about the thickness of a fine
hair, flexible, often varying in diameter in the same filament, green,
nearly cylindrical, with two slightly prominent, colourless, pellucid
angles, opposite to each other. Joints not so long as broad, bicrenate
at each of the two angles, separating readily at the articulations.
There can be no doubt that this is a true species of Desmidium,
and I am inclined to think with Captain C a r m i c h a e l ,
that it, and not D. Swartzii, has probably been described hy
some authors as Conferva dissiliens. The filaments of this
species are so nearly cylindrical, as to authorise the use of the
term, in opposition to triangular. They are also more unequal
than in D. Swartzii, and do not present the singular
pimiatifid appearance which that species exhibits at a certain
stage of its growth.
Fig. 1. D . cy lin d ricum, natural size.
Fig. 3. D e ta c h ed jo in ts ; magnified.
Fig. 2 . Filaments in different states.
T i n