It probably is a Stomatella, although something looks "wrong" about it. I THINK I can see the nuclear whorls of the shell just above and to the right of the arrow point? Color is extremely variable on these snails, most common is probably a yellow background patterned with darker colors. Hmm, I think what looks wrong is the animal color...it's usually cream or white, except for the "nigra" variants that are black. Also, the papillae usually aren't so visible. It may be a species other than Stomatella varia, but the shell looks flat enough to be that species.
Cheers,
Don