I am in the process of replying to Greg's detailed query, but the main issue is that as Frances implies the quarterlands were not anciently self-contained entities. As Margaret Killip hinted, neighbouring farms previously shared certain resources, and had allocations of others. Most of the interlocking and intermixed pieces got straightened out, but the 'ideal' of a unitary quarterland with no detached or dangling bits was not always reached. See Broderick's Place-name Survey under Lezayre for examples which survived a long time. (Clenagh and Ballacottier)