CENSUS: 1841: at home age 10 with parents, Kersquarter Cottages, Sprouston, Roxburghshire, Scotland.  1851: this must be him as a shepherd at Girrick, Nenthorn, Roxburghsire, Scotland (the same area his parents are in). Look at the names! The head of the house is "Patrick Johnston". James brother is one "rev Patrick Johnston Riddle". There is a servant "Margaret Oliver", James married "Jane Oliver". There is a "Thomas Riddell" that must be his cousin? 
MIGRATED: Scotland to New Zealand approx 1860. Onboard the ship "Matoka". James came out to New Zealand under contract to some farmer in the South Island but broke the contract on arrival in Wellington. I believe it was owing to his wife's health.
OCCUPATION: He was engaged at Wellington as a shepherd by George Hunter on his Terawhiti Station and remained with him for eleven? fourteen? years.
Purchased farm at Wiatotara but this was returned to Maori owners by the Government. As compensation James was given a farm at Karihaka near Waverley.
1899 : RESIDENCE : Waverley. Recorded on son William's South African War record.
NAME CHANGE: His name changed from Riddle to Riddell when a mistake was made on the title of the new house on the farm and James was advised just to go with it. He added the initial J. to his name in later life for buisness purposes to avoid confusion with the miriad other James Riddles and James Riddells in NZ. (This is probably in reference to his son James J Riddell..)
DEATH: NZBDM: 1919/3633
BURIAL: Waverly cemetery, Wanganui, New Zealand. Plot 18, block 7. Findagrave record