I would also recommend that folks look at

Schoonover, L.M., 1941, A stratigraphic study of the mollusks of the
Calvert and Choptank formations of Southern Maryland: Bulletins of
American Paleontology, v. 25, no. 94B, p. 165-303.

Here Schoonover studied the fossils from the Calvert and Choptank
Formations. There were fossils from the upper Chesapeake Bay area which
intergraded with ones from the lower bay area though they were identified
as different species. I believe that the conclusion was that these fossils
were one species and what we were seeing was ecotypic variation. She
studied several such sets. I also recall that this may have been part of
her doctoral thesis.


> This is a "must read" for those who think that ever little difference in
> shell morphology constitutes a new species.  The variation from site to
> site is remarkable.
>
> dick p.
>   ----- Original Message -----
>   From: Roland Anderson
>   To: [log in to unmask]
>   Sent: Tuesday, December 06, 2011 5:24 PM
>   Subject: [CONCH-L] reprint of book
>
>
>   I'd like to bring to your attention that the book "Local Races and
> Clines in the Marine Gastropod Thais Lamellosa Gmelin, A Population
> Study" has been reprinted and is available quite reasonably from Amazon.
>   Roland
>
>   --
>
>   Roland C. Anderson, Ph.D.
>   Biologist Emeritus
>   Seattle Aquarium
>
>


Regards,
Charlie
.................................................
Charlie Sturm

Past-President
American Malacological Society 2010-2011

Research Associate - Section of Mollusks
Carnegie Museum of Natural History
Pittsburgh, PA, USA

Associate Professor - Family Medicine
Fellow-American Academy of Family Practice
Fellow-Academy of Wilderness Medicine

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