I have had a few Xenophora specimens with unusual attachments.  A  few
specimens with land snails attached, which presumably were carried into the
ocean by a river.   One with some kind of bone attached, probably a piece of
a fish skull.  One X. pallidula had attached a piece of wood about 2 inches
in length, with a nail sticking through it.  One had a soda bottle cap
attached.  Another carrier had attached an auger (Terebra) shell, the
opposite end of which was still attached to a large chunk of another carrier
shell which had previously owned it.  On a couple of occasions I've seen a
carrier with a shell attached which was several times more valuable than the
carrier itself - like the specimen in a friend's collection, with three
small Conus bengalensis attached.  I've seen glass pieces on a few carriers.
My favorite was the specimen with the built-in locality data.  A Xenophora
pallidula from the Philippines had attached a triangular piece of brown
glass, with the single word "Philippines" printed across it in white.  This
curious carrier costume component was later identified as a piece of a San
Miguel Beer bottle.

Paul M.