Dear Elizabeth,
 I read Geerat Vermeij's book about 2 years ago, and enjoyed it very much.  He
really opened my eyes to the natural history of mollusks in a deeply personal
way - I will never look at shells quite the same way again.  I searched out
another book by him, called "The Natural History of Shells" which is very
scientific, yet written for the layman, and very readable, which, as the title
suggests, discusses his research in relationship to the reasons shells are
formed the way they are.  It's published by Princeton University Press.
 
Mary Graham in NH