Identifying your specimens as seashells, not as snails, is advisable.  Many landsnails are serious pests, so their import is often illegal.

Knowing enough about the specimens to sound impressive can be useful.  My brother had a backpack full of fossiliferous rocks at an airport.  When it came through opaque on the X-ray, he proceeded to take out the rocks and started explaining their geologic setting and the types of fossils, and was quickly sent on his way.  I imagine that commencing a lecture on molluscan systematics and biology would have the same effect.

Checked luggage is not always handled carefully; I put delicate specimens in carried luggage if possible.

    Dr. David Campbell
    "Old Seashells"
    Biology Department
    Saint Mary's College of Maryland
    18952 E. Fisher Road
    St. Mary's City, MD  20686-3001 USA
    [log in to unmask], 301 862-0372 Fax: 301 862-0996
"Mollusks murmured 'Morning!'.  And salmon chanted 'Evening!'."-Frank Muir, Oh My Word!