Although not related to James Prior, I think that this is Matthew Peat and his new family in 1881:
Hill Cottage, Lochrutton, Kirkcudbrightshire
Mathew Peat, m, 37, Railway surfaceman, b. Lanark
Mary, w, 27, b. Kirkcudbrighshire
Mary, d, 6, b. Troqueer
Elen, d, 5, b. -do-
Annie, 3, b. Kirkcudbrightshire
Jane, 1, b. -do-
There is a marriage between Matthew Peat and Mary Morgan in Lochrutton in 1874.
Gadget