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274: PROCEEDINGS OF SOCIETIES. 
like those of Xanthidium fasciculatum, but somewhat broader, 
and tapering upwards to the blunt and uncinate extremities. 
In the same rich gathering the zygospore of Arthrodesmus con- 
vergens presented itself, and it also does not seem to be before 
known. It forms a contrast to both the foregoing, being quite 
smooth, and altogether destitute of spines. This is a fact some- 
what singular in the free short forms of Desmidiacee. 
Mr. Archer was likewise able to show fresh specimens of the 
zygospore of Cosmarium margaritiferum in many stages. It is 
arrayed with spines very like those of the zygospore of C. Botrytis. 
Spherozosma vertebratum, too, was there also conjugated, and it 
was worth noting that the zygospore of this species is beset with 
numerous slender, subulate, acute spines. ‘This was the third 
occasion in which Mr. Archer had taken this species conjugated ; 
and, that the zygospores are spinous deserves a note, making an 
exception amongst filamentous genera in that fact, just as Arthro- 
desmus convergens and a few others make, on the other hand, rare 
exceptions amongst the short free forms, in having smooth zygo- 
spores. In all books Spherozosma vertebratum is, unfortunately, 
erroneously stated to have smooth, non-spinous zygospores. 
In this same gathering Mr. Archer was also able to show fresh 
zygospores of Stawrastrum controversum and Staurastrum Dickiei,. 
both rare, as well as of Hwastrum binale, and several others mor 
frequently met with in the conjugated state. . 
Mr. Archer was quite disposed to hold that, if we were only as 
familiar with the zygospores of the different species of this Family 
as with the mature forms themselves, we might be able to deduce 
from the former quite as good characters as are presented by the 
latter; for instance, the difference between the spines of the 
zygospores in the two related species, Xanthidiwm fasciculatum 
and X. aculeatum. It was indeed very beautiful to see all these 
varied species distributed over the slide, sometimes in pairs ready 
for conjugation, the contents now partially emerged, and again, 
the zygospore more and more adyanced and in different stages, 
each parent individual unerringly making choice of its own spe- 
cies—the rare, as it were, seeking out the rare, and the abundant 
freely conjugating with the abundant. 
Resolved, that the members of the Club desire to express and 
place on record their unfeigned sorrow at the announcement of 
the death of Professor Harvey, one of their two honorary mem- 
bers. 
June 21st, 1866. 
Dr. Moore showed samples of the substance found in some 
quantity, scattered on the ground, houses, &c., by Mr. R. A. 
Duke, C.E., in the neighbourhood of Templemore, County Sligo, 
after a night’s rain, and which had been sent to the Rev. Pro- 
fessor Haughton under the impression that it was sulphur. This 
