< We live on the water in Ocean Pines, Maryland and are on a canal connected to the bay and Atlantic ocean.
>We have a large animal of some type that lives in our canal and I cannot either dig it out or identify it.
>This thing resembles a long neck clam but the neck is about one and a quarter inch in diameter and about six or eight inches in length.  If you try and find it with a clam rake, it will retract and I have tried in vain to dig it out but with no avail.   It must be better than 18 inches down. The neck is a  whitish material and looks like a piece of plastic pipe which it retracts into the hole.  It is about one and half inches in diameter and when you try and locate it it disappears for a couple of weeks before you can see it again.<

If the environment is somewhat silty or muddy, the angel wing (Cyrtopleura) is a good possibility.  It is known to burrow at least two feet down and in able to move up and down in the burrow.  Catching one is very difficult.

    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!