Calliostoma zizyphinum

[wolfi]

Hi,
Trochidae are tricky, sometimes....... . I'm not sure about the first specimen you called "Calliostoma" (on the left side). The second specimen (on the right side) might be Gibbula divaricata (L., 1758) or Gibbula rarilineata (Michaud, 1829).
Sorry  , but personally I don't think your "Osilinus turbinatus" (= Monodonta turbinata) is an Osilius (or Monodonta) species at all. The genus was named Monodonta because of the little dens (a flat tooth) at the columella, which I can't see in your specimens.  Furthermore, the Osilinus species get much larger than your specimens and the general shape of the shell is different (as far as I can see from your pictures).
Please excuse me, but it's often helpful to take a "frontal view" picture from the shells: axis of the shell exactly vertical, opening (= aperture) facing to the camera. Then it's much easier to judge the shape of the whorls, the sutures and the general shape.
For example: frontal view of a shell:

I hope I could help a little bit........ .
Kind regards: wolf 
Edit: sorry, Poseidon, I was too late (it takes too much time for me to write in English  , you are absolutely right. Sorry, again......... .