Hi Linda,
I believe #1 and #3 are both Chlamys vesiculosa (Dunker)
#2 is a juvenile. With so many ribs, it is probably either C. multistriata
(Poli) or C. varia (Linne). These two are virtually impossible to
distinguish as juveniles.
#4 could be a form of C. flexuosa, but I lean toward C. glaber (Linne).
Paul M.