Conchology

from WordNet (r) 3.0 (2006)

conchology
    n 1: the collection and study of mollusc shells [syn:
         {conchology}, {shell collecting}]

from The Collaborative International Dictionary of English v.0.48

Conchology \Con*chol"o*gy\, n. [Conch + -logy.] (Zool.)
   The science of Mollusca, and of the shells which they form;
   malacology.
   [1913 Webster]