A HISTORY OF SURREY is extended. These implement-bearing deposits occur for the most part on the slopes of the existing valleys at varying heights above the present streams ; but at Limpsfield worked flints have been found in an ancient gravel which, though probably originally belonging to the Darent drainage system, now lies on the watershed between the Darent and the Medway at an altitude of 500 feet above sea level. It is of course in the larger valleys that the valley-deposits attain their widest development ; hence in Surrey we find that the old river- gravels and flood-loams, and also the more recent alluvium, are thickest and most extensive in the vicinity of the Thames. The older gravels fringe the valley irregularly, in somewhat ill-defined terraces at varying elevations, throughout its extent, but are generally widest near the confluence of the larger tributaries with the main river. At the lower levels they are well seen between Walton and Petersham ; between Richmond and Wands- worth ; and between Wandsworth and Deptford ; while the remnants of high terraces are found on Kingston Hill, Wimbledon Common, Rich- mond Hill and Putney Heath ; and again at Clapham, Balham and other places. 1 It is however on the northern side of the river in Middlesex and in Essex, and on the southern side in Kent, that the Thames Valley Drifts reach their greatest importance both in extent and in fossil con- tents. Among the mammalian remains which they have yielded in these counties we may mention those of the wolf, lion, hyaena, bear, bison, musk-ox, reindeer, Irish elk, horse, elephant, mammoth, rhinoceros, hippopotamus, beaver, etc., some being of species now extinct ; and along with these are many land and freshwater shells, all except two or three belonging to species still living in England. It is in association with these mammalian remains that the Palaeolithic implements are found, in some places in considerable abundance ; and in the study of these rude implements the sciences of geology and archasology join hands. In Surrey, as instances of the occurrence of the fauna, we may mention that elephant remains have been obtained from Thames Ditton, Kingston and other places in the Thames Valley, and Palaeolithic implements at Cookham, East Sheen, Battersea Rise, Wandsworth, Lewisham and other places ; in the valley of the Wey similar relics of elephant have been found in the neighbourhood of Shalford, at Waverley near Farnham, in gravels 150 feet above the present river between Alton and Godalming (where Palaeo- lithic implements are very abundant, especially in the pits near Wrackle- sham), and again along with a flint implement at Pease Marsh ; in the valley of the Mole remains of elephant have been obtained at Charlwood, Dorking, Betchworth and Petridge Wood Common, with those of rhi- noceros also at the last named place ; remains of the horse, rhinoceros and elephant at Sutton 2 ; the horse, rhinoceros, reindeer and roebuck from Among recent papers on this subject, and for references to previous literature, consult H. W. Monckton, Quart. Journ. Geol, Soc., vol. xlviii. (1892) pp. 29-47, and vol. liv. (1898) pp. 184-195 ; and Proc. Geol. Assoc., vol. xiii. pp. 74-81 ; and A. E. Salter, ibid. vol. xv. (1898) pp. 264-286. 3 See W. W. Watts, Quart. Journ. Geol. Soc., vol. Iv. (1897) p. ii. 26