Found in a rock pool at low tide. Quite small so is hard to ID. Looks like a Polinices - possibly putealis or tawhitirahia? or Tectonatica zonulata? It’s glossy white and much more solid than a small Mammilla simiae, also a different shape to the Notocochlis gualtieriana that wash up occasionally here. Measures only 10mm tall. Any ideas?