Osborne Series
a series of beds of Oligocene age, found at or near Osborne, in the Isle of Wight . They were deposited in fresh and brackish water.
There are, of animals, peculiar species of Paludina, Melania, Melanopsis, and Cypris, and of plants, Chara. One bed is the Nettlestone Grit, near Ryde, which is a freestone much used for building.
Called also the St. Helen's series.