Snail eating parasite?

[Thereefdoc]

I noticed these little snails on my turbo. I’ve never seen them before. The shell is whitish with some of them having tiny purple markings. After looking closer I also see them in the rocks. Please help. The day started with the storm knocking out our power, still not back, and now this.
The color somewhat matches a pyramid snail but the shell is completely different.

 

[James M]

Could be Collonista snails