This is a representation of the coat of arms of the Roman Catholic Archdiocese of Boston.
Azure, a cross fleurettee or; issuant from a base bary wavy of five, of the first and argent, a mount of three coteaux of the second.
The following Commons images were used to create this image:

 File:Roman Catholic Diocese of Erie.svg by Niagara (talk · contribs) (mitre)
 File:Old French Escutcheon.svg by Masur (talk · contribs)
 File:Coa Illustration Cross Fleur-de-lys 2.svg by Madboy74 (talk · contribs)
Own work
Alekjds