PROCEEDINGS OF SOCIETIES. 
Dublin Microscopical Club. 
2\st January , 1869. 
Dr. E. Percetal Weight exhibited a species of Corticate 
Sponge, from the collection made by him in the Seychelles, from 
the peculiar structure of which he was inclined to believe that it 
should be referred to Bowerbank’s genus Pachymatisma, of which 
only one species was known, Pachymatisma Jolinstonia— Amphi- 
trema M‘Callii, Scouler, MSS. The oscula in the Seychelles species 
were few in number and simple, pores inconspicuous. The oval 
siliceous bodies in the corticate layer were as in Pachymatisma ; 
but some few appeared to have a dark central nucleus ; the inter- 
stitial spicules were cylindrical and also “ cylindro-patento- 
ternate sarcode spicules stellate. 
Mr. Archer drew attention to a Heliozoan Rhizopod, being the 
same he exhibited at the Club meeting, 19th September, 1867, 
and which he had little doubt was the same as the first of the 
forms figured and expatiated on by Dr. Focke in Siebold and 
Kolliker’s ‘ Zeitschrift fur Wissenschaftliche Zoologie,' Bd. xviii, 
Heft iii, p. 345, t. xxv, which had just reached his hands, and 
which he now exhibited. He would, however, defer any further 
enlargement upon it for the present, until he had an opportunity 
to bring forward another closely allied form, which two together, 
he thought, excellently represented a new and distinct genus. 
The essential character of this genus would be that the central 
body, bearing long slender pseudopodia, is enclosed within a 
stratum of a quite different looking sarcode, itself giving off pseu- 
dopodial processes of its own, different in character from those 
emanating from the central body. This genus, which he would 
call Heterophrys, and the present form Heterophrys Fochcii, he 
hoped to figure and describe on a future occasion. 
Rev. E. O’Meara showed a peculiar Diatom taken from the 
stomach of an Ascidian from Belfast Lough. It presented the 
general appearance of Nitzschia bilobata, but the surface of the 
valve between the striate border and the margin of the hoop 
was covered with wart-like excrescences irregularly disposed. 
Five or six examples were found in the gathering, all presenting 
the same peculiar feature. He considered it a variety of Nitzschia 
biblobata, and suggested for it the distinctive name of verrucosa. 
Dr. Moore exhibited examples of the Prothallia of Ferns, 
showing the archegonia ; he explained the morphological structure 
