Gabriel Gudding might be interested in the following, if he doesn't already know about it. I just ordered a rare book from Scotland for the library, titled A Conchologist's Text-book, by Captain Thomas Brown, published in Glasgow in 1833.

In doing so I noticed that the library already owned the following, "published for the author by Haswell, Barrington & Haswell" in Philadelphia, in 1839 : The conchologist's first book; or, A system of testaceous melacology, arranged expressly for the use of schools, in which the animals, according to Cuvier, are given with the shells, a great number of new species added, and the whole brought up, as accurately as possible, to the present condition of the science. The said author is listed as EDGAR ALLAN POE. A note to the library record : "Stated by R.W. Griswold, in the International Monthly Magazine, Oct. 1850, to be a copy nearly verbatim, of the text-book of conchology by Captain Thomas Brown, printed in Glasgow in 1833."

Was one of Eddy's heteronyms a certain Captain Brown?