Hello Olivier,
Do you know where any of these shells came from? That would be a big help.
I can help you with a few of them anyway. Here are my best guesses:
#1 Looks like a subadult Melongena, and the operc also looks like
Melongenidae. Not sure what species. Perhaps Melongena patula??
#2 Looks like a small Hyotissa hyotis L.
#3 This is a species of Arca, but can't venture a guess without seeing the
rest of the shell.
#4 Anadara sp. Not Anadara granosa.
#5 Looks like Semicassis diuturna Iredale
#6 Semicassis persimilis Kira (often considered a subspecies or form of
Semicassis bisulcata)
#7 ? not familiar with the species kobelti.
#8 Hecuba scortum L. (family Donacidae)
#9 not Latiaxis nakayasui. Probably L. spinosus.