Date unknown. Saint Merryn is the titular patron of a place in Cornwall.
He may be identical with the Breton saint honoured at Lanmerin and
Plomelin. During the medieval period, the legendary Saint Marina was
believed to have been its patron. For this reason, the Cornish St.
Merryn observed the feast on July 7, whereas the Breton feast was on
April 4
(Farmer).