Local moraines are found in some of the valleys in Pomona and Hoy.
The very names of the islands indicate their nature, for the terminal a or ay is the Norse ey, meaning "island," which is scarcely disguised even in the words Pomona and Hoy.
Shorthorns and polled Angus are the commonest breeds of cattle; the sheep are mostly Cheviots and a Cheviot-Leicester cross, but the native sheep are still reared in considerable numbers in Hoy and South Ronaldshay; pigs are also kept on several of the islands, and the horses - as a rule hardy, active and small, though larger than the famous Shetland ponies - are very numerous, but mainly employed in connexion with agricultural work.
Hoy (q.v.; 1216) is the southernmost of the larger islands.
Flotta (372), east of Hoy, was the home for a long time of the Scandinavian compiler of the Codex Flotticensis, which furnished Thorrnodr Torfaeus (1636-1719), the Icelandic antiquary, with many of the facts for his History of Norway, more particularly with reference to the Norse occupation of Orkney.