I have both books.  I will not comment on the "scientific" validity of
either one as I do not use either one to identify shells.  I purchased
both of them as examples of what was available, in the popular literature,
to the 19th. century amateur collector.

There may be differences due to the approach of each author, one being
male the other female.  I know that S j Gould wrote a piece in Natural
History (magazine) a few years ago about Mary Robert's book.
Unfortunately I do not have the reference with me.

Both are interesting works, but I admit I have only read small portions of
each.

Charlie
******************************************************************************
Charlie Sturm, Jr
Research Associate - Section of Invertebrate Zoology
                     Carnegie Museum of Natural History, Pittsburgh, PA
Assistant Professor - Family Medicine

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