Help ID snail?

[LaLa001]

I am new to the hobby and have found 4 of these guys pop up over the weekend. I have a 90 gallon saltwater tank with live rock and live sand. I have yet to add anything else to the aquarium as I am still in the quarantine process.

Thanks for your help!

 

[Crabs McJones]

Looks like a stomatella. Does it sort of have a little half shell on its back?

 

[LaLa001]

Looks like a stomatella. Does it sort of have a little half shell on its back?

That's what I was thinking at first but when I was able to get another view the shell seemed like it was covering the majority of it.

 

[ahiggins]

My thought is stomatella too

 

[KJ]

Stomatella snail