Bryozoan

This is a bryozoan, probably Discoporella. It forms around a sand grain (yours formed around a dark grain) and then grows outward into a domed shaped colony.

2 hours ago, Al Dente said:

This is a bryozoan, probably Discoporella. It forms around a sand grain (yours formed around a dark grain) and then grows outward into a domed shaped colony.

You know, that is more in line with what I thought originially. A voljnteer at Aurora told me it was fish dermal bone, so I went with it. Thank you for the correction. I will make the change.