Toggle button to occlude geometry missing I cannot see this button anymore, even though I am in edit mode.

Is it possible to hide or delete it accidentally? I need this button back pretty badly, since I dont want to select nearby geometry that would normally be hidden.
Do you mean this button? 



It only shows up when you are in Solid View or higher. If you are in wireframe mode, it will not show up because it cannot compute the occlusion.