A quick search on IGI and ancestry.co.uk revealed one possible line -

James Marr son of Thomas Marr and Cath Crellin, christened 12 Sep 1841 in Maughold. Thomas and Catherine married 26 Nov 1836 in German. Possible that Catherine is daughter of William Crellin and Margt Corkell[Corkill] christened 3 Mar 1816 in German. William and Margaret married 12 April 1812 in Marown. Many children for William and Maragaret listed on IGI.

In 1861 Thomas Marr is widower living in Malew:
RG9/4424, Enumeration district:3b, Folio:46, Page:13,Household Schedule:55, Mountain Common(?)
Thomas Marr Head, Wid, 48, Miner, Scotland
William Marr Son, Unm, 22, Miner, German
Agnes Marr Daug, Unm, 14, House maid, Patrick
James Marr Son, Unm, 16, Lead washer at mines, Marown
John R. Marr, Son, 12, Washer at lead mines, Malew
Thomas Marr, Son, 10, Scholar, Patrick

All the children listed can be found on the IGI.

William and Margaret Crellin are still around in 1861:
RG9/4420, ED:4, Folio:60, Page:9, Household Schedule:36, Lamb Field.
William Crellin, Head, Mar, 68, Gardener, German
Margt Crellin, Wife, Mar, 75, Gardeners Wife, German