17062012 Egg or embryo cases, but of what. Don't look like whelk eggs

17062012 Egg or embryo cases, but of what. Don't look like whelk eggs

Observation - 17062012 Egg or embryo cases, but of what. Don't look like whelk eggs. Description: these look like rabbit droppings, but I suspect they are maybe whelk embryo cases, though usually the ones I see hereabouts are either yellow or already hatched pale yellow/white. Any ideas?

these look like rabbit droppings, but I suspect they are maybe whelk embryo cases, though usually the ones I see hereabouts are either yellow or already hatched pale yellow/white. Any ideas?