Andrew and Andreas,
 
Thanks for the correction!  The suffix "ense" has bugged me for years
(one of those things you always wonder about, but never get around to
dealing with).  I was leaning in the direction of considering it an
improper (perhaps antiquated) form of "ensis" (obviously without any
evidence to support such a conclusion).  I'm glad to know it has a
legitimate meaning!
 
I'll take this opportunity to ask about another tidbit that has
always puzzled me.  Maybe our European members can shed some light,
since the question concerns them.  Why do Europeans use the genus
name Nassa to describe those species in the family Nassariidae which
Americans (and most other folks) refer to as Nassarius?  Nassa I
believe is a Muricid genus.  Any ideas on this?
 
Paul M.