Azure, a chevron or between three horsebits argent.
Vert, ten escallops argent, four three two and one.
CREST: out of a ducal coronet or, an eagle's head erased proper, charged at the neck with an escallop argent.
The shell is associated with St Augustine, and with pilgrimages to Santiago de Compostela in Spain (pilgrims at one time used such shells to scoop up water from streams along the way).
The ordinary crest coronet, or, as it is usually termed in British heraldry, the ducal coronet, (Ulster, however, describes it officially as “a ducal crest coronet”), is quite a separate matter from a duke's coronet of rank. Whilst the coronet of a duke has upon the rim five strawberry leaves visible when depicted, a ducal coronet has only three. The “ducal coronet” is the conventional “regularised” development of the crest coronets employed in early times.