
                                                  West Chester, Pennsyl. Aug. 18. 1831


 Dear Sir,
               Yours of the 12th, inst. was received the day be-
 fore yesterday: and I took the earliest opportunity (having 
 no student to do it) to comply with your request, for a 
 list of the genera described in Hooking's 2nd No. of the Flora
 of the Northern Parts of [British?] America, & a list of those species
 which are not ennumerated by Pursh & Nuttall.  You will find
 it on the enclosed sheet: & I hope in such form as to be
 satisfactory - or at least intelligible.


      I shall be glad to see your edition of Lindley's Intro:
 duction; - as I think it will be highly valuable, in this
 country, to those who have not had a chance to study the 
 natural method.  Since my last letter, I have received
 a copy of the work from London - which I shall be glad
 to exchange for one of your edition, if I can find
 any body willing to have the London copy - which is not
 very likely.  It has occured to me, that it would be
 extremely useful to American students of the Natural
 method, if you were to annex a Glossary of the Terms
 used in that arrangement; as I have found it dif:
 ficult to understand them satisfactorily.  Our common
 elementary works do not explain the terms of the Natur-
 al systems; & those who have not access to a Glossary, or Dictionary.


      With respect to Cardamine rotundifolia - (if we have
 not wholly mistaken the Arabis rhomboidea) I shall
 give up all pretensions to distinguish species, if it be
 not entirely distinct from the Arabis, of [Persoor?].

        