
          that are very distinct: and I have large
 drawings of all the species.


 Prof. Silliman kindly offered to aid me
 in getting liberty for me to examine bird-feet
 & take casts of them at some of the museums
 in N. York & I have requested him to make
 enquiry before he goes on. If he gets permission
 say at the American Museum I have made up
 my mind to come on (D.[?].) at the time mentioned
 alone: expecially since you inform me
 that probably I might get casts of the feet
 of some living birds. I shall also hope to get
 liberty to examine your copy of Bucklands
 work. Since I last wrote to you I have found at
 Springfield one or two poor specimens of the
 singular footmark which you suggest may
 be his Chenotherium. Is that a biped genus?
 I believe all those are which I have discovered


 I am glad to learn that Mr Cooper
 is not yet decided as to the footmarks. From his
 letter I was led to infer that he had decided
 a priori that they could not be bird tracks
 or that ^ [inserted: he feared] I should [serve?] him as Eaton did in
 respect to his vegetable crotalus. I blame
 no man for delaying to form an opinion on this
 subject. I did so myself till forced by the facts
 to adopt certain conclusions.


 My supplemental paper on
        