Once again I'm stuck. I received great help on- species and syn: ( about
nerites )
  I have Nerita atra ( Gmelin,1791 ) it has a  Syn: senegalensis ( Gmelin,1791
)
  I understand a syn: being the same shell with a different author, but here
we
  have the syn with the same author with the same year. Should I be looking
for
  the syn: being a different nerite, or did he forget he already named the
nerite a
  week before.
  Thanks again for the help
                             Jr