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the last ; some of which, from the fact that they are 

 numerous in certain localities and present evident signs of 

 having travelled, may have been deposited in patches of 

 older river-gravels, much denuded, and at the present day 

 difficult to make out. Other implements of related types 

 were found scattered over the highest parts of the Green- 

 sand hills and the Chalk downs, which are much weathered 

 by surface exposure but not collected in patches of river 

 gravel, though some have been found in the masses of 

 angular flints which have been derived from the clay-with- 

 flints. Besides these there are implements whose differences 

 of form and size place them under a category apart from 

 the last, while their resemblance to certain implements 

 from the caves of France and England, together with the 

 situation in which they have been found, suggest another 

 and perhaps later type and age. The high level gravel of 

 the Thames between 200 and 100 feet O.D., contains 

 implements very much worn, together with perfectly fresh 

 ones, accompanied by abundant sharp flakes. The lowest 

 gravel of the " Old " Darenth at Erith, also contains 

 implements, and in the same deposit at higher levels and 

 of a later period, abundant flint relics oh the actual spots 

 of manufacture may be seen, as also in similar situations 

 elsewhere. This enumeration of positions in which 

 implements are found, is intended to give my idea 

 of relative age by the sequence. In the latest Trails 

 [T.J also are found wasters and small implements, 

 such as " thumb-scrapers " hollow scrapers, &c., resembling 

 both those of the older deposits and those found on the 

 present surface of the country. I have picked out flakes 

 from the ancient rain-wash or warp, immediately covering. 

 those Trails, and also implements of flint, rudely chipped, 

 never polished, of lengthened form and having frequently 

 a peculiar and intentional turn aside in one part of them, 

 which are found on the surface, but which differ from those 

 found exclusively on the ground. Then we have unpolished 

 and partly or wholly polished tools. The implements of 



