35. Transversa X litera, summo capite circumflexo, Christum
in scutis notat. Cacilius de M. P. c. 44. Cuper (ad M. P. in
edit. Lactant. tom. ii. p. 500) and Baronius (A.D. 312, No.
25) have engraved from ancient monuments several specimens -
as thus, + or * of these monograms, which became extremely
fashionable in the Christian world.