BX (properly called AC) cable contains a separate bare metal strip between the metal armor and the craft paper wrapping over the conductors. Usual practice is to fold this strip back over the end (holding the anti-short bushing in place), and wrap it around the armor several times before trimming the end off. The bonding strip is then clamped to the armor (and to the box) by the connector or box clamp.
The armor (and bonding strip) is the EGC, and as such MUST be bonded with a proper connector at all terminations.
