198 
Crowe coincided, but rather looked upon the lobate outgrowths 
as simply departures from the globular typal form due to the ex- 
cessive activity of the self-division of the constituent cells taking 
place at certain points of the group. The individual cells were, 
indeed, mutually in closer proximity than Nageli depicts — a cir- 
cumstance probably assisting to bring about the departure from 
the simple globular figure of the family or group. The slow 
vibratory movement was a curious circumstance, seldom seen in 
objects so large as these specimens, and one upon which he 
could not venture to offer au opinion. 
Mr. Crowe exhibited specimens of Labrodagnite. 
Mr. Archer exhibited specimens taken in Co. Tipperary of 
Sphcerozosma Jiliforme (Ehr.), Auct. This minute and well- 
marked little form appears to be very rare ; and, except very 
sparingly by Eabenhorst, has not seemingly been met with since 
its original record by Ehrenberg. It is at first glance well dis- 
tinguished from Sphcerozosma excavatum by the elliptic form of 
the segments, separated by an acute constriction and its larger 
size, and from Sphcerozosma vertebratim by the double processes 
(not single as in that species) connecting the joints. It is dis- 
tinguished, too, by a different colour, not being of the same bright 
green, and by its smaller size. Examples of both the common 
forms, along with Sphcerozosma Jiliforme, Mr. Archer exhibited 
side-by-side. 
Mr. Archer likewise drew attention to a form of Gonatozygon 
Ralfsii (de Bary), from the same gathering, presenting the pecu- 
liarity that the little roughnesses characteristic of this species 
(and of G. Brebissonii), which ordinarily give little more than a 
granular appearance to the surface, were here extended into short 
vertical, acute, almost spine-like prolongations, giving the joints 
a somewhat remarkable appearance. These little processes were 
of somewhat different lengths, and seemed to give this form a 
claim to be regarded as a near approach to a spinous filament. It 
would be in the recollection of the Club that Mr. Archer had once 
the opportunity of showing at a former meeting some specimens of 
this species from Yorkshire, which he owed to the kindness of the 
Rev. Prof. Gagliardi, in which the roughnesses were reduced to a 
minimum, giving a simple dotted appearance, thus showing the 
amount of variation this species seems subject to in this regard. 
Those specimens were, however, in a barren condition ; but the 
present now exhibited showed a number of conjugated examples, 
and in that condition it quite accorded with the usual form in all 
respects. 
Dr. Barker showed Desmidium aptogonum, new to Ireland, taken 
on the recent occasion of his and Mr. Archer’s visit to Conne- 
mara. This is a form which has never yet turned up near Dublin. 
The present was the triangular variety; both seem to be rare and 
partially distributed, but the triangular form appears to be (like 
the triangular form of D. Swartzii) more common than the quad- 
rangular. The triangular form of D. Swartzii is, however, per- 
