I often get asked this question so here is my standard response:
There is no legal coat-of-arms for the Phethean family. There has been a hand-drawn one that someone showed me many years ago but it is a contrivance and I refuse to depict it as it is thoroughly misleading, and in the UK would be illegal to display.
Arms were awarded to a person, not a family, and the arms could only be inherited by permission. So even if one member of the Phethean family had been granted arms, only his direct descendants would be entitled to display them. Arms pass from the owner to his eldest son and then to his eldest son and so on. Other members of the family may, depending on their relationship and their surname, be able to apply for a ‘differenced’ version of the Arms to be granted to them.
I have researched the “Visitations of Cheshire” for both 1580 and 1613 and the nearest you can get is the FITTON family – who are not related!
So, sorry, but we are all just “commoners”! (well, I like to think “yeoman farmers”, which is what we were before the Industrial Revolution sucked us in to the big cities)