ID this: not a trochus

[SteveG_inDC]

LFS said these were trochus snails. They look more like limpets to me. ID?

 

[Irishtimm]

LFS said these were trochus snails. They look more like limpets to me. ID?

They look like Spiny Star Astraea snails to me.

 

[JGT]

^^spiny star astreas. Great algae eater,