Notes
This is the form recommended in the national standard reference work, A Gazetteer of Welsh Place-Names (University of Wales Press, 1967). One should not deviate from its recommendations without good reason.
According to the rules of Welsh orthography s should be followed by the consonant g not by the consonant c. It is not easy, however, to hear the difference between the combination sg and the combination sc in speech (compare ysgol/yscol).