Mark,

Color and texture may be somewhat similar between the A. heliotropium and
the Angaria but that still leaves begging the question of the opercs.  The
angaria have Trochidae opercs rather than the calcareous Turbinidae opercs.

Pass the nerites indeed!  Around here we say pass the winkles (after an old
Rolf Harris song that I expect no one to know).

Tom Eichhorst in New Mexico, USA (where the humidity was 85 yesterday -- of
course the temperature was only 75: F).