DUBLIN MICROSCOPICAL CLUB. ool 
umbilicus is in focus, the margin is unseen. The central rosette 
consists of about eight large areoles of unequal size, generally 
flattened. The areoles are small, irregularly quadrate, area radiate, 
the radii united in fascicles of about ten each, the areoles of equal 
size throughout. Viewed under a low power the valve is iridescent 
and looks like Actinocyclus Ralfsii, from which, however, in all 
other respects it is obviously distinct. Mr. O’Meara was about to 
prepare special descriptions and figures of this and other forms met 
with in this material. 
Section of Coal with embedded Crystals ——Mr. Porte exhibited 
a section of Derbyshire Coal, which he had prepared' in order to 
show its woody structure; be found unexpectedly that it was tra- 
versed obliquely across the woody fibres by aseam of some crystal- 
line substance (nearly a sixteenth of an inch in width), which 
polarized beautifully and not unlike Salacine. Mr. Porte sug- 
gested that its formation was owing to a fissure in the coal into 
which the crystalline matter in a state of solution percolated, and 
that it was afterwards subjected to a temperature sufficiently high 
to fuse the erystals, their structure appearing to him to indi- 
cate crystallization from a state of fusion rather than from solution, 
but what the substance is he would not at present venture to say. 
Nuclei in two Heliozoan Rhizopoda——Mr. Archer drew. at- 
tention ‘to fugitive preparations. of two Heliozoan Rhizopods 
treated with Beale’s carmine solution, in order to show the “nu- 
cleus” (Hertwig) or “ central-capsule” (Auct.), but without which 
treatment these structures could not be recognised. These were 
Heterophrys Fockii and Raphidiophrys viridis, Archer. The 
former was-an exceedingly fine example, composed of eight con- 
joined individuals; the junction when living being by’ a narrow 
isthmus or band of sarcode, as well as by numerous ordinary pseu- 
dopodia, these mostly projecting around in every direction, had 
been unusually strong and long. The nuclei—in the living state 
invisible—now came out as minute sharply bounded globular bodies, 
strongly imbibing the dye. The examples of the other rhizo- 
pod, Raphidiophrys viridis, were remarkable for being, on the 
other hand, nearly all composed of but a single “ individual,” 
densely charged, as usual, with abundant and rather large chlo- 
rophyll granules. It is remarkable that here, in each example, 
several subglobular bodies, not before evident, became highly dyed 
by the carmine—quere, all nuclei—and betokening the ultimate 
subdivision of the aggregate body-mass into so many subdivisions 
of a future colony, that is, an ordinary compound example? It 
is a pity the comparative rarity with which these heliozoan forms 
turn up render the opportunities for experiment so isolated and 
postponed. 
