Henthorn.

[tracey clarke]

There is a record for an Adam Henthorn age 30 born about 1841 Ireland in the 1871 Canada census for Montreal. Quebec.
Do you know who  he is ? 

[Mike Henthorn]

The Adam Henthorn you refer to was born in 1827, not 1841.  He is the brother of my great great grandfather Thomas Henthorn who was born in 1824.  Both emigrated through New York in 1846 during the Irish famine.

I looked at the census records and recognize his full family.

You found an Adam Henthorn age 63 who died in 1831 in Ireland.  That person may be this Adam's father.  If the mother was left a widow during the famine, would make sense the boys  aged 22 and 19 would emigrate.