PROCEEDINGS OF SOCIETIES. 129 
minute, oblong; constriction deep and linear; segments rather 
longer than broad, quadrate; all the angles rounded; sides and 
ends rather deeply concave ; frond compressed ; side and end view 
elliptic; empty frond minutely punctate. 
Mr. Archer was quite disposed to regard this plant exhibited 
by Dr. Barker as not Cosmariwn quadratum. It is a good deal 
smaller, and wants any notable inflation at each side at the base 
of the segments; besides, the ends are concave, and not convex, 
as in C. quadratum. It might, perhaps, by those who had not 
seen Cosmarium sublobatum (Euastrum sublobatum, Bréb.), be mis- 
taken for that species, which it most decidedly is not. The pre- 
sent form is often seemingly quite or nearly as much expanded at 
the ends as it is at the base, whereas in Cosmariwm sublobatum 
the segments very considerably taper towards the ends, and that 
species is also larger than the present, and wider in proportion to 
its length. Ewastrum pusillum, Bréb., appears to have some affinity 
with Dr. Barker’s plant, but Mr. Archer had not seen specimens 
of that form; it appears, however, to be smaller, the upper angles 
to be acute, not rounded, and the concavity at the ends with a 
well-defined obtuse angle at the centre, not gradually curved. On 
the whole, Mr. Archer was himself quite disposed to regard the 
present plant as undescribed ; the somewhat punctate empty frond 
would form a further distinction. 
Mr. Woodworth exhibited a great variety of photographs of 
microscopic objects, some of them high-power objects, and all very 
excellent. 
Mr. Archer showed in fructification specimens of a diccious 
(Edogonium, which, pending, indeed, information on one point as 
regards it, he would refer to Cdogoniwm gemelliparum, Prings- 
heim. The present plant showed the oogonia, its lateral aperture 
(micropyle) high up, the oospore nearly filling the oogonium, the 
separate male plants with their antheridia forming series of very 
short cells, more or less numerous. But the point requiring 
elucidation as to the identification of this plant with Pringsheim’s 
species, just mentioned, was whether there were two spermatozoids 
evolved from each antheridial cell by a division taking place in 
the direction of the length of the parent filament, or whether only 
one spermatozoid was produced from each daughter antheridial 
cell, the division taking place, as ordinarily, transversely ; and it 
was just this point he had been unable to make out. He had 
found this plant for some weeks in a pool hard by the “ Rocky 
Valley” near Bray, and had on several occasions taken specimens 
always showing oogonia, but not until now had he found the male 
plants, which, indeed, had been first detected in these specimens 
and pointed out by Dr. J. Barker. 
Dr. E. Perceval Wright exhibited some specimens of a beautiful 
pink Podura. Various species of Nullipora grow in great quantity 
in Bantry Bay, and they are dredged up for the purpose of being 
