Anepigraph

Bust of Galla Placidia to the right, draped with Chi-Rho on right shoulder, wearing a diadem of pearls, a double necklace of pearls and long earrings.

Chi-Rho inside laurel wreath.

Photo of a coin sold the 14/01/2003 by Classical Numismatic Group, Triton VI, lot 1138, link to the sale: https://www.acsearch.info/search.html?id=122082, link to their website: https://www.cngcoins.com/.

Variant with Chi-Rho on the right shoulder and medium-sized wreath on the reverse (wide space between the wreath and the beading).

Apart from a coin whose authenticity remains to be confirmed, all the Tremissi that I have seen show a bust with a double pearl necklace.