Dear George;-
    I have just visited the picture of your Epitonium. It appears to
be consistant with E. Cycloscala laxata. I have two and they are both
from Phuket. The blades of the costae should be thin and somewhat
irregular. The size is also consistant.  I don't seem to have a
confirming picture I can refer you to at the moment. The depth is
also consistant with those in my collection
       Art