have a look at wills on Brian's site - Lonan regs are poor (marriage reg appears to be missing tho possibly Bishop's transcripts might help) - my reading of wills is
John Scarffe [will 1742] + Marg Quark [will 1760]
sons John (eldest), Thomas, James (? will 1770) , Philip, Daniel;
John will 1748= Margt Cowle 3 ch but only John (bp 1746 survives)
John = Margt Killip

son James () b 1771 (?will 1833) m Cath Kneal in 1797

son James b 1804 ....

however there are a few other wills of Jame Scarffe's that might repay attention and confirm things

as one of the wills mentions property this + earlier wills may allow you to push back a couple more generations