
          give me a short article onthe history of
geology & mineralogy of the U.S. It 
would be particularly acceptable. Pray 
think of it. I mean the history of progress
of the science and its prinplal results.

Can you send me specimens of the following
Ferns - desiderata in my herbarium? Equisetum
[?] (I have received [?] from
Canada); Lycopodium tristachyum, [?]
Ophioglossum bulbosum, pusillum
Botrychium dissectum, fumarioides, obliquum
Acrostichum aureum, Aspidium [crenatus?]
obtusatum, atomarium, [rufidulum?], Onoclea 
obtusilobata, Asplenium pinnatifidum
angustifolium montanum
Pteris pedata, gracilis, Blechnum 
serrulatum, Woodwardia thelypteroides
Cheilanthes dealbata, Hymenophyllum 
ciliatum, [?] americanum, Azolla 
caroliniana. If you can help me to any these
I shall be truly obliged. I want some others
for my corrspondents for which I shall trust
of the kindness of Dr. Barratt. Your set of
Carices will be much acceptable and I will
do what I can to send you the Scottish ones.
Now I am among the Cyperacea I may ask why
you have joined Eriophorum tenellum Nutt to E.
polystachion. The latter has leave slat and broad,
the peduncles of the spikes smooth and the silky
hairs (in this country) about 3 times as long as the
spike in E. tenellum.  The leaves are narrow almost
triangular, the puduncles both round and downy
and the hairs scarcely twice as long as the spike.
I think you will find these very distinct.

Bentham is come to reside in London & to study the
        