Dear Carol;- Clench & Turner (Jonsonia #31) spell it "pourtelesii". The other one is "celesti". Another example of similar shells from different places is E. zelebori Dunker, 1866 from (where else?) NZ; and E. blainei C&T, 1953 uncommon from Florida. There are no distinguishing characteristics in the two shells. DNA studies may prove different, but I don't know of anyone doing such work. Art