Hi carolanne,
William & Ann Mellard had their first two children baptised at Wath, James on 8/11/1829 and Mary Ann on 9/9/1832. William Mellard/Meller/Mellor was a miner. 50 years ago, the pronunciation of Mellard sounded like Mellerd and the d was almost silent, so I assume it had been like that for generations in the West Melton / Brampton area. If people could not complete their own census return, then the enumerator could easily record the name incorrectly.
Varah, the son of James, returned to the West Melton area and is recorded as Mellard in the 1871 census boarding with his father's half uncle (see reply #7).
Regards marshall