Standard of the Legion
The Vexillum Legionis is an adaptation of the standard of the Roman Legion. The eagle which surmounted the standard is replaced by the Dove, the emblem of the Holy Spirit. Beneath the Dove a cross-bar bears the inscription "Legio Mariae" (Legion of Mary). Intermediate between cross-bar and staff (and joined to the former by a rose and a lily) is an oval frame bearing a representation of the Immaculate Conception (the Miraculous Medal). The staff is set in a globe which, for use on a table, stands on a square base. The whole design conveys the idea that the world is to be conquered by the Holy Spirit acting through Mary and her children.
a. A representation of the vexillum should appear on the official notepaper of the Legion.
b. A model of the vexillum should stand on the table at meetings about six inches (15 cm.) in advance of, and about six inches (15 cm.) to the right of the statue. The table model customarily used is inclusive of the base, 12¾ inches (32 cm.) in height. Vexilla in metal and onyx may be obtained from the Concilium.
A large model will be required for processional purposes . It should be about 6½ feet (2 m.) high, of which about 2 feet (60 cm.) would represent the length of staff below the globe. The remainder should be made according to the design (see picture below) on the scale of one foot per inch (12 to l). The staff fits into a base (not part of the vexillum) to hold it erect when not being carried.
That beautiful standard of the Legion of Mary." (Pope Pius XI)