Consider it from a non-conchological point of view. How many of us
conchologists would glance out our dining room window and remark, "oh look,
there's a Turdus migratorius hopping around on the lawn". Yet an
ornithologist, or even a serious bird watcher, would probably say just that
- and might very well look with scorn upon us laymen who use common names.
As for us ornithological laymen though, we are just as happy that the thing
can be called a "robin". So we can hardly blame them for calling something a
winkle or a whelk or a clam, or whatever makes their life easiest.  Well
gotta run - the cafeteria is serving Xiphias gladius L. 1758, and I want to
get there while they still have some.

Paul M.