Re: Mathias' sen?

I have a MADSEN in my line, but he is a "son of Matz."My "MATHIESEN" -- the generation where the patronymic becomes fixed as a surname (ca. 1784) -- is the son of "Mathias/Mathies."It looks to me like these are two different patronymics for two different given names, one monosyllabic and one disyllabic.Or am I mispronouncing "Matz" and "Mathias/Mathies"?