Gary,
Natica ampullaria Lamarck, 1822 was described from unknown locality, so some
difficulties arise.
The first to suggest the synonymy with N. heros was, I think, Philippi, 1852.
According Mermod, 1953 N. ampullaria was assumed as synonym of the well known
Euspira catena (See Bouchet & Waren, 1993)
Ciao from Italy
Riccardo Giannuzzi-Savelli
Gary