106 WILLIAMSON, ON FORAMINIYFERA. 
though a few occur in the shallower Laminarian zone, especially towards 
its outer border. In the latter instance they are to be found amongst the 
interlacing roots of the Laminariz, and especially amongst the tufts of 
corallines with which those roots are so frequently surrounded. How far 
their habitat extends into deeper water we have as yet no means of deter- 
mining, since it is difficult to say whether the shells brought up from such vast 
depths in the middle of the Atlantic* were living or dead at the time they 
were collected. The same remark applies to the majority of the specimens 
that have been forwarded to me by my dredging friends. I have found such 
numerous examples of corallines with the sessile Foraminifera abounding 
upon them as clearly prove that they both lived on the same ground. The 
Foraminifera do not appear to affect districts where the ocean bed consists 
of gravel or coarse clean sand, but preter localities where there is much 
fine-grained oozy sediment. ‘This especially applies to the more delicate, 
minuter varieties. 
“The method of obtaining specimens must vary according to the object 
in view; if the collector merely seeks dried shells for his cabinet, indifferent 
whether living or dead, the process of floating them is by far the most 
productive. A few pints of the sand must be collected from beneath, at 
least, two or three fathoms depth of water, and thoroughly dried ; it should 
then be passed through a coarse conchologist’s-sieve, or tlirough a piece of 
coarse net, so as to eliminate all the rough material. ‘The finer portions 
passed through the sieve must be poured into a bowl containing cold 
water, and well stirred up, so that the whole may become saturated. On 
being allowed to stand a few moments the more delicate of the concame- 
rated shells, rendered buoyant by the air contained within their chambers, 
readily float to the surface, whilst the sand and mud settle to the bottom.t 
A little manipulation enables the collector to blow off this scum, so rich in 
treasures, into an empty vessel, and the addition of fresh water further 
cleanses the objects from impurity ; the creaming of the bowl being repeated 
so long as any sediment or impurity remains. ‘The water may now be 
drawn off by means of a syphon, and the objects dried, when they are 
easily collected for examination. J have found it desirable to carry the 
process a stage further before drying the shells, in order to obtain the 
cleanest specimens: sweeping them off the moist sides of the bowl by means 
of the forefiuger, I transfer them to a small evaporating dish containing a 
solution of caustic potass,t in which I allow them to boil over a spirit-lamp 
for some moments, thus dissolving the organic matter and leaving the cal- 
careous shells free from impurity. The moment the lamp is removed the 
shells settle to the bottom of the vessel, since the fluid has filled all the 
chambers of each shell, displacing the air. The solution must now be 
poured off, and the shelly residue be well washed in clean water; otherwise 
drying will leave an efflorescence of alkaline matter on the specimens, mar- 
ring their beauty. After washing they may be dried, when they are ready 
for examination. : 
“The advantage of the process here recommended lies in the facility with 
which very unproductive sands are made to yield their tribute of specimens. 
I have often obtained but a few hundreds of shells from several pints of 
sand. It is obvious that the examination of such large quantities of ma- 

* See Dr. Bailey’s Memoir in the ‘Smithsonian Contributions,’ vol. ii, 
1851. 
+ Care must be taken at this stage to break up the air-bubbles floating 
on the surface, since these buoy up numerous inorganic particles which 
require to be precipitated. 
t The Lig. Potasse, P.L., is a convenient form for this purpose. 
