Looking for Cournow Family from Cornwall

My Curnow ancestors live for at least four (and probably more) generations in Mawgen, Meneage, Cornwall. I know of Jonathon Curnow 1742-1829; Thomas Curnow 1780-1857; John Curnow 1812-1868; Avis (Eva) Thomas Curnow 1853-1922. The Curnows immigrated to Australia around 1840-1850.