Folktale diffusion and ethnolinguistic variation

I’ve been stop-starting my way happily through Celtic Fairy Tales and More Celtic Fairy Tales, two late-19thC collections by the great Australian folklorist Joseph Jacobs, combined in a plump Senate paperback and handsomely illustrated by John D. Batten:

Ancient people names in Ireland

Gearóid Mac Niocaill’s book Ireland before the Vikings (Gill and Macmillan, 1972) has an interesting passage on the names adopted on the island during the 4th, 5th and early 6th centuries. He refers to “a mosaic of peoples” who are “dimly perceptible” amid the settlements and political changes he has been discussing, and whose names appear in various forms:

ending in -raige (‘the people of’), or as Dál (‘the share of’) or Corco (perhaps ‘seed’) plus a second element, or as a collective noun ending in -ne. Some contain animal names, such as Artraige ‘bear-people’, Osraige ‘deer-people’, Grecraige ‘horse-people’, Dartraige ‘calf-people’, Sordraige ‘boar-people’; others, such as the Ciarraige, the Dubraige and Odraige, have a colour (ciar ‘black’, dub also ‘black’, odor ‘dun’) as the first element; others, such as the Cerdraige, seem to have an occupational term as the first element.