Headon Beds

Headon Beds, a subdivision of the Oligocene (q.v.) of the Isle of Wight, so named by Edward Forbes, which vary in thickness from 133 feet at Headon Hill to 175 feet at Whitecliff Bay. They consist of green shelly sands and marls or limestones, mainly of fresh-water origin, but with some brackish and marine beds in the middle of the series. They rest conformably upon the Upper Bagshot Sands, and are similarly overlaid by the Osborne series. Among the most characteristic fossils are Planorbis euomphalus, Lymncea caudata, and L. longiscata, and Viriparus levnta in the freshwater beds, Potamides cinctus in the brackish ones, and Cgtherea (Venus) incrassata and Neritina concava in the marine ones. At Hordwell or Hordle Cliff, near Lymington, the lower part of the series has yielded turtles, snakes, an alligator, a crocodile, the fresh-water bony-pike Lepidosteus, several birds, the ungulates Palceothevium and Anoplotherium, the insectivorous Spalacodon, and the carnivor Hyccnodon. At Brockenhurst the marine Middle Headon series has yielded numerous fossils, including fourteen species of corals.