Cypraeidae (true cowries) and Columbellidae (dove shells) are two families
that come to mind that contain both carnivores and herbivores. Actually,
it's hard to classify some mollusks as one or the other. Some grazers are
omnivores, taking in sessile animals along with algae. If you eat eel grass
or turtle grass, you'll get bryzoans and hydroids too. If you slurp up mud,
you might get nematodes and foramiferans.
 
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Gary Rosenberg, Ph.D.                     [log in to unmask]
Malacology & Invertebrate Paleontology    gopher://erato.acnatsci.org
Academy of Natural Sciences               http://www.acnatsci.org
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