Coat of arms of Jermyn

The blazon

sa. a crescent betw. two mullets, in pale, ar. — Crest, a greyhound s head sa. gorged with a bar gemelle or. (Another crest, out of a ducal coronet or, a greyhound s head ppr. collared or ; another, a talbot, passant, gorged with a coronet.)

A blazon is the description of a coat of arms in the technical language of heraldry. The drawing comes from that text, and from nothing else.