For an excellent account of special investigations in the high terraces above the Thames, see J.Allen Brown, F.G.

S., Palaeolithic Man in Northwest Middlesex, London, 1887.

For discoveries in America, and the citations regarding them, see Wright, the Ice Age in North America, New York, 1889, chap.xxi.Very remarkable examples of these specimens from the drift at Trenton may be seen in Prof.Abbott's collections at the University of Pennsylvania.

For an admirable statement, see Prof.Henry W.Haynes, in Wright, as above.

For proofs of the vast antiquity of man upon the Pacific coast, cited in the text, see Skertchley, F.G.