Thomas became a merchant citizen of London. Nisbet in his book, "A System of Heraldry," 2nd Edition, Vol. II, page 10, Edinburgh 1814, says he was "son of deceased Robert Lidderdale, younger son of St. Marys Isle in Scotland." His coat of arms are blazoned with the motto "Pro belle qui providet" which is new and was only used by him."
Source: Robert Halliday Lidderdale, An Account of the Lowland Scots Family of Lidderdale, 1950.
[This Thomas Lidderdale is described by Nesbit as merchant citizen of London, son to the deceased Robert Lidderdale, a younger son of St Mary's Isle.
Arms - Azure, a chevron ermine, within a bordure ingrailed, argent.
Crest - An eagle's head erased, proper.
Motto - Per belle qui proevidet.]
Source: P.H. McKerlie, History of the Lands and Their Owners in Galloway, 1878.