
          New York, May 28th 1839

My dear Sir,

I have just received from
Sir Wm.[William] Hooker the accompanying Nos
of the Annals of Natural History, in
which you will find some very interesting
articles.

Have you seen the fine Fossil Infusions
from Stamford? A student brought me
a large lump of it, but knew nothing of
its nature. As I had examined such matters
a good deal I knew what it was at the
first glance. It consists entirely of fossil
siliceous shields of infusoria, exactly like those
figured by Dr. Bailey. I send you a sample.
They show finely under Raspail's microscope. I
have [added: just received] some splendid fossil infusoria from Dr. Gray,
among then a new one discovered by Ehrenburg
at Eger in Bohemia, where it occupies a space
        