Legg on Sponge Sand. 
19 
Observations on the Examination of Sponge Sand, with Remarks 
on Collecting, Mounting, and Viewing Foraminifera as 
Microscopic Objects. By M. S. Legg, A. I. A. (Read 
June 22, 1853.) 
Various papers on the structure of the Foraminifera have 
been brought before the Society by Mr. Williamson and others, 
but the impression conveyed by those communications has 
been that the shells in question are not very easily obtained, 
and consequently they are likely to be passed over by micro- 
scopists from the want of specimens by which to study 
them. 
Although the matter of this paper has no pretension to 
originality, I am induced to offer these remarks in compliance 
with a suggestion thrown out by a Member of our Council, 
that if Members would occasionally communicate facts, appa- 
rently unimportant in themselves, or new modes of manipu- 
lation under the general title of ' Microscopic Memoranda,' 
such remarks would contribute to diffuse a taste for the pursuit 
by facilitating the labours of those whose time and inclination 
admit of such researches. 
Under this impression I now lay before the Society the 
result of my experiments on sponge sand, and the methods 
employed to bring the specimens more immediately within 
my reach without the labour of picking them out from an in- 
discriminate sample of the sand itself. 
Having observed that there was some degree of uniformity 
in the magnitude of certain species of the Foraminifera, it 
occurred to me that by sifting the mass of sand through wires 
of different gauges important results would follow, and I 
therefore obtained some specimens of wire-gauze of 10, 20, 
40, 70, and 100 wires to the inch, and, having also procured 
from a sponge merchant about a peck of the rubbish arising 
in sorting the sponges, I proceeded to separate the sand into 
parcels of different degrees of fineness. 
In the first process (employing a gauze with 10 wires to the 
inch) I cleared the mass of clippings of sponge, small pebbles, 
&c., without obtaining any specimens of shells worth retaining. 
In the second (20 wires to the inch) 1 obtained some very 
nice specimens of the Orbiculina adunca and complanata, but 
scarcely anything else; these specimens, of which the Mem- 
bers may recollect that Dr. Carpenter exhibited a series of 
very beautiful drawings at one of our soirees, were thus brought 
together, instead of being, as before, scattered through the 
mass, at intervals few and far between. 
c2 
