My guess would be Scalpomactra scalpellum but I'm not sure.
From a handful of beach sand at the high tide line on the island.
1mm grid
This upload is intended to be representative of the most prolific shells in this sample. I have put aside about 60-70 shells that I think are Eatoniella. I may of course be wrong on some, but enough are clearly repeats of shells I have uploaded at other times that I don't think endless repeats are useful.
I'm happy to be contacted if anyone is studying them in future and would like to see what is there.
From a handful of beach sand at the high tide line on the island.
1mm grid.
The overall shape is pretty distinctive for M coronata but I'm not sure about the aperture. Unfortunately I didn't get a square-on photo of it. Do I need to try again?
From a handful of beach sand at the high tide line on the island.
1mm grid
From a handful of beach sand at the high tide line on the island.
1mm grid
From a handful of beach sand at the high tide line on the island.
1mm grid