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spermntozoids ? Thus the oogonium would be external to the plant, 
and a structure independent therefrom. But there was no evident 
place of origin for spermatozoids, unless, indeed, some of the 
empty vegetative cells around might have given birth to them. It 
is a pity that Pringslieim has not as yet completed the subject by 
giving the history of this “seventh” species; we should then be in 
a position to see the true bearing of the present very crude observa- 
tion ; but incomplete as it is, Mr. Archer ventured to think it worth 
while to call attention to the specimens now shown, never having 
before seen this condition in this plant. 
‘24th June, 1869. 
Rev. E. O’Meara exhibited examples of Trinacria excavata from 
Jutland, of Professor Heiberg’s own collection, kindly forwarded 
by Mr. G. M. Browne. Mr. O’Meara desired, likewise, to record 
Toxoniclea Gregoriana and Cocconeis excentrica in the same gather- 
ing from the coast of Donegal ; he also showed Trinacria regina 
and Soleum exculptum. 
Professor E. Perceval Wright exhibited a new parasitic crustacean, 
of which he will prepare a detailed account. 
Mr. Archer exhibited an example of the zygospore, same as 
shown by him last year of a Cosmarium, which he thought may often 
be confounded with Cosmarium margaritiferum, but seemingly not 
named, and very distinct therefrom — distinct, indeed, in its zygo- 
spore from any other form whatever. This is large and covered, 
not with any kind of spines or processes, but with a few large 
hemispherical hyaline tubercles, not unlike the “bull’s eyes” in 
glass. 
Mr. Crowe showed Closterium linea (Perty) conjugated in con- 
siderable numbers. Its zygospore, at first sub-cruciate, ultimately 
becomes elliptic, lying longitudinally and freely within the space 
formed by the union of the parent pair of conjugating cells. 
Mr. Archer drew attention to some examples of an organism he 
had now several times noticed, and which, though not at all at first 
sight a striking-looking thing, was seemingly not a little puzzling. 
This ordinarily presents the appearance of a spherical, sharply- 
bounded, and thinly-walled cell, containing green contents, averaging 
say in diameter. It might, perhaps, call to mind a small 
specimen of Eremosphcera vindis — that is, when a cell of that or- 
ganism exceptionally gives origin to four in place of two daughter- 
cells. But somewhat like as this may be, there could be no doubt 
at all that it was not a condition of that organism, yet, perhaps, 
one might a priori regard it as another “species” of Eremosphsera. 
It could, however, hardly be even so. These cells, as has been 
mentioned, are ordinarily spherical, but they sometimes present them- 
selves of an elongate figure, broadly elliptic, or fusiform. Some of 
the green contents appear to be distributed in a scattered manner 
within the cavity of the cell, whilst ordinarily a number of green 
granules are disposed in a parietal stratum within the investing cell- 
