islands of Anglesea and of Wight (Fig. 95), and the estuary of the Thames to the west of a line drawn due north from Felixstow. The other modification in the contour of Great Britain and Ireland consists of a narrow strip parallel to the present coasts. The forest of yew, oak, ash, birch, Scotch fir, and alder, extended from the Prehistoric sea-level up the mouths of the rivers, and joined that covering the general surface of the country. In the marshes of the lower Thames it is met with at a few feet above low-water mark.
Fig. 95.—Neolithic Britain.
This forest growth is proved to belong to the Neolithic division of the Prehistoric period by the presence of animals originally domestic, and introduced by the Neolithic tribes, the Celtic short-horn and the sheep or goat, as well as by the absence of the Pleistocene mam-
