My small dictionary defines "Malacology" as "The branch of zoology which
deals with mollusks" and defines "Conchology" as "The branch of zoology
which deals with shells or mollusks".  This would make them the same.
Generally, however, don't most people restrict conchologists definition
to the shell, and malalacologists to include all aspects of molluscs
including the shell, habitat, biology, etc.?
 
I glanced through five or six well known shell books such a "Compendium
of Seashells".  They didn't define the two terms, but Abbott used
"amateur conchologist" several times.  In "Murex Shells of the World",
Radwin and D'Attilio define "Concologist.  A specialist in the study of
molluscan shells. See also Malacologist" and "Malacologist. A specialist
in the study of mollusks, especially one who deals with soft parts as
well as shells.  See also Conchologist".
 
I don't think using "Conchologist" is running down their contribution
compared to a "Malacologist".
--
                     Aloha from Wesley M. Thorsson
Editor of Internet Hawaiian Shell News, a monthly Internet Publication
           122 Waialeale St, Honolulu, HI  96825-2020,  U.S.A
       http://www.hits.net/~hsn                 [log in to unmask]