The landowner survey was completed in 1876 and published that same year in a London book. Only other info. on James Murdock was that for some reason his representative/s returned the survey (possibly he had recently died?) and his slightly more than two acres were valued at only 10 shillings. (i.e., 2 A. 0 R. 30 P.). The address/es given were where he apparently lived. More information can be found at IreAtlas at http://www.seanruad.com
Griffith's Valuation CD and civil registration of b/m/d and the Valuation Office, Dublin (for a fee), would be your resources to try and trace him. Also, perhaps he left a will?