200 
actual pseudopodia. But as Claj3arede and Lachmann record the 
occurreuce of a form which they identify as Actinophrys brevicirrhis, 
Perty, as frequent near Berlin (‘ Etudes sur les Infusoires et les 
Bhizopodes,’ p. 450), this supposition appears not at all tenable, 
as it is most unlikely that the whole three observers could have 
fallen into the error of taking the present form for a member of 
the genus Actinophrys at all. Nothing, indeed, could be more 
sure than that this new form, now exhibited by Mr. Archer, ap- 
pertained to Acanthocystis, and there seemed as little doubt that 
it was an undescribed species. Mr. Archer would postpone giving 
a description of this pretty little Bhizopod, as he hoped to be able 
shortly to do so, accompanied by a figure, and would meantime 
content himself by naming it after Perty, Acanthocystis Pertyana, 
as commemorative of his labours ; although, for the reasons men- 
tioned, it can hardly be identical with his form, notwithstanding 
a certain amount of resemblance. 
Dr. Moore exhibited a Sirosiphon, so intimately intergrown 
with Jungermannia concinna as almost to lead to the idea that 
they might be genetically related — a state of things rendered, 
indeed, out of the question by reason of the essentially distinct 
nature of the cell-contents in each, not to speak of the decided 
licheuous nature of the former. 
Mr. Crowe exhibited sections of “ Lough Neagh petrified 
wood ” and of Carrara marble. 
Mr. Archer exhibited a new Staurastrum, from Galway, cha- 
racterised by the possession of a number of crenatures, seen in 
front view bordering the outline, which considerably resembled 
that of Staurastrum orbiculare, both in contour and size. These 
crenatures were due to a number of short truncate, compressed, 
somewhat emarginate processes, the upper six of which in figure 
were comparable to that of an open book made to stand verti- 
cally. He showed the end view, as seen in an empty half-cell, 
which presented a very pretty appearance, and which rendered 
apparent the form of the crenatures adverted to. He would, how- 
ever, defer a proper detailed description till another opportunity, 
and give this species the name of Staurastrum maamense, now 
merely drawing attention to this curious kind of ornamenta- 
tion, due not to spines, nor to “ pearly ” granules, but to thin 
erect processes, bent vertically at an obtuse angle, thus not 
throughout in the same plane, and these somewhat emarginate at 
the upper edges. 
Bev. E. O’Meara submitted to inspection a slide, containing 
many interesting diatomaceous forms, dredged from a depth of 
2000 fathoms in the Gulf Stream, lat. 47° 3' N., long. 23° 21' W. 
This slide had been given to him by Professor E. P. Wright, and 
was portion of some deep-sea soundings taken by Commodore 
Chimmo, of the Gannet, which had been submitted to Dr. Wright 
by Professor Haughton, for a report thereon. He invited special 
attention to a form belonging to the genus Euodia, which in out- 
line and sculpture presented such divergence from the two forms 
