Jonas Mertz is listed by Floyd as a son of Jacob and Sarah Jury. He is designated U1f.

Jonas can be found in the 1850 Census in Upper Paxton Township. He is a tailor (his father's occupation) age 35 and lives with Caroline 25 and Susannah P 5 and Benjamin 3 and Isaiah 1. Also present, but out of order and listed after Benjamin are Catherine 11 and Henry 14. Most likely these are children of Jonas by a first wife or they could be children of, say, a deceased brother -- but I'm aware of none.

I've listed all of these children here as belonging to both Jonas and Caroline since I do not know the name of his first wife if he had one.

Then in 1870, Jonas is living with Mariah age 31 -- a third wife I assume -- and Jonathan M 17 and Clinton E 4 months.

He died at the PA Lunatic Hospital according to his death certificate.

His sons too seem to show up in one census and disappear the next (though I didn’t find him in 1860).

I took the approach to see if any had death certificates listing Jonas as their father. The only one I found is for John B born in 1847 (he must be Benjamin in the 1850 Census) who listed Carline Collier as his mother.