
          Prof. Torrey

Dear sir
I herewith return to 
Dr. Gray, who kindly takes charge of them, - the
parcels of lichenes and Potamogetons which you
where so kind as to send me for examination.
The lichens I have looked through
with interest, but did not find any of your spe-
cimens nor of Mr. Halsey's which I had hoped
to avail myself of in the citations of your Enu-
meration, + his - the Northern lichens being al-
most without exception from myself.
I was so unfortunate, in examining one of
the Potamogetons which has glued down, to set
on fire the edge of the paper, without however
injuring the specimen at all. As the best reparation
I can offer for this unfortunate occurence which
I deeply regretted - I have put up with the specimens
        