>Dear Andrew,
>
>Sort of like a toothpick?

Exactly.

>I have read that the ceratus (labral spine) is used to ream out barnacles.

Oh, to be a barnacle...

>The classic paper of François (1891) reports use
>of this structure as a lever to pry apart the
>valves of living pelecypods - like "getting a
>foot in the door" according to Radwin and
>D'Attilio (1978)

I would imagine the Ceratostoma spine is not
strong enough for this (but I may be wrong); I
have collected numerous specimens, and spine
breakage is not common.

Geerat Vermeij (hey, does his last name translate
as "molester of worms"?)  visited us a few years
ago. He was investigating labral modifications of
fossil gastropods likely to be used in levering
open prey. When you look closely (these
modifications are often subtle), there are quite
a few species, including a lot of buccinids,
including Austrofusus and Busycon.
--
Regards
Andrew