68 LONDON DISTRICT. 



is specially convenient. 1 The prolific gravels and loams of 

 the High Terrace in the Swanscombe area were investigated 

 by Messrs. Smith and Dewey : the most important pit, 

 Barnfield, lies just beyond our eastern margin near Greenhithe ; 

 implements of Strepyan, Chellean, and Lower Acheulian groups 

 were there found in definite vertical succession. 2 The Middle 

 Terrace has yielded late Acheulian types, while from its surface, 

 overwhelmed by Coombe Rock or Trail, numerous Mousterian 

 implements have been obtained from localities as far apart as 

 Northfleet (4J miles east of Dartford) and West Dray ton. A long 

 list of occurrences which bear out the correlation of the Upper 

 and Middle Terraces with the Strepyan, Chellean and Lower 

 Acheulian and with the Upper Acheulian and Mousterian culture- 

 stages respectively could be compiled, but, with our limited 

 space, it is bstter to point out certain anomalies. 



Near Piccadilly Circus and elsewhere in Central London 

 beautiful implements of Chellean type in fresh unabraded con- 

 dition have been found at the base of a deposit attributable 

 on stratigraphical and palseontological grounds to the Middle 

 Terrace : specimens may be seen in the London and the British 

 Museum. It ssems impossible to reconcile this occurrence with 

 the geology or, indeed, with the archaeological discoveries else- 

 where, and we must wait for future work to provide a consistent 

 account of human culture and its relation to physical history in 

 the Thames Valley. The importance of recording accurately the 

 position of any implements found, and of submitting them to 

 some authority competent to decide their culture-stage, cannot 

 be over -emphasised. 



In the Colne Valley there are two noted localities Croxley- 

 green and Mill End ; the former is shown on our map as situated 

 on ' Plateau Gravel ' which has in part been resorted in Upper 

 Terrace times ; the latter appears to be the Middle Terrace ; 

 yet the Croxley green implements are mainly early Acheulian, 3 

 those from Mill End Chellean, 4 so that here, again, there is a 

 problem awaiting solution. 



Along the upper margin of the Middle Terrace, between West 

 Drayton and Acton, many fresh implements of Mousterian date 

 have been found; they mostly lie on the surface of the gravel, 

 beneath a cover of Upper Terrace material that has slipped from 

 the higher ground ; at Acton a * working-floor ' was discovered 

 by Allen Brown, whose many writings on this district should 

 be consulted 5 : rolled Chellean forms are frequent in the gravels. 



The implements from the base of the Middle Terrace in 

 Central London have been mentioned above ; in South London 



1 Geol. Mag., 1902, pp. 98-99. 



2 Archceologia, vol. Ixiv, 1913, pp. 177-204; vol. Ixv, 1914, pp. 187-212. 



3 Beevor, Sir H., Proc. Geol, Assoc., vol. xxi, 1907, p. 245. 



4 Archceologia, vol. Ixvi, 1915, pp. 195-224. 



5 e.g., Proc. Soc. Antiq. Lond., 2nd series, vol. xi, 1887, pp. 211-216; 

 ' Palaeolithic Man in N.W. Middlesex,' 1887: Proc. Geol. Assoc., vol. x, 1888, 

 pp. 361-372, and vol. xiv, 1896, pp. 118-120. 



