need a ID for this

[Delphinus]

There are (apparently) some species of cerith snails that look exactly like pyramid snails from the top. But, like other ceriths are herbivores so you'd find them on the sand and on the rock and stuff like that -- but not the clam or on other snails. From what I understand anyways.

Even if they're not pyramids in this case, the fact that they are glommed onto the astrea like that, would be a cause for concern for me. They're not there to keep the astrea company ....