Transversa X literâ, 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 -
or of these monograms, which became extremely fashionable in the Christian world.
"The History Of The Decline And Fall Of The Roman Empire"—Chapter 20