Gijs said:

< As far as I know, both Olivella and Oliva are buried
beneath the surface during the day, and only emerge at night
for foraging.>


Not in this part of the world, where at least Olivella
semistriata, Olivella columellaris, Olivella volutella, and Oliva
undatella are abundantly (or even massively) active in the
daytime.

kate