David,
   I learned the technique while washing and screening Devonian microfossils
for Dr. J. R. Tillman at Ohio Wesleyan University. I collect mass samples
for fine material and sieve one screen at a time, catching material that
passes through a given screen with a dishpan underneath to be saved for the
next-smallest screen.  The point is to concentrate shells and other things
into a uniform size fraction; or else large shells would hide tiny ones. I
look for larger shells, i.e., 3-4 mm and larger by spreading the sample out
on a  black piece of cardboard or other dark surface. The fine fractions go
under the dissecting microscope to be picked on a picking tray. I use a
wetted camel's hair brush (00000 size) to pick up the material that is
around 1 mm and smaller. I mount the tiniest shells and tests on
micropaleontology slides with gum tragacanth since it does not shrink
significantly when drying. It is also easily soluble in water to allow me to
remove specimens for donations or for correcting misidentifications.

>From: David Kirsh <[log in to unmask]>
>Reply-To: Conchologists List <[log in to unmask]>
>To: [log in to unmask]
>Subject: Re: Micro Shells
>Date: Sun, 26 Mar 2006 11:07:03 -0500
>
>Hi Wallace,
>
>I'm interested in learning more about this technique. Are you screening at
>the beach or at home? Do you use magnification to scan each sieve for the
>micros? If so, how carefully do you check?
>
>I've never actually seen it done, so I don't have a point of reference.
>
>Thanks,
>
>David
>
> >
> >I am late in replying, but my strategy to get micros is to use a stack of
> >sieve screens.
>
>"There is still very limited awareness of the nature of the threat. This is
>an era of specialists, each of whom sees his own problem and is unaware of
>or intolerant of the larger frame into which it fits. It is also an era
>dominated by industry, in which the right to make a dollar at whatever cost
>is seldom challenged." -- Silent Spring, Rachel Carson (1962)
>
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