I recently saw a pic of a (16thC)breastplate with this. Typical knight praying on knees on one side of bp, crucifix on other with s&cb at base. Simple skulls, skulls with bones nearby are easy to find, but this one definitely had them crossed. Where?
Yup, later on, it's a masonic thing. Every now and then they find buttons with that device while excavating the 1600-1700's Spanish missions here in Florida.
The device is to remind one of ones own mortality.
