84 ME. C. DAWSON : SUPPLEMENTAEY NOTE ON [April 1 9 1 4,. 



The character of these flints is often so changed as to resemble 

 ironstone, and some can be scratched and disintegrated with a 

 penknife. This feature may well account for the apparent absence 

 of flints overlying the still higher and older strata in the Weald. 

 They have a roughly- smoothed surface, but bear no striations or 

 'frost-fractures.' The presence of flints of so large a size, and 

 comparatively little worn and rolled, in the middle of the Wealden 

 area, is a point of great interest. No implements or ' Eoliths ' 

 have occurred in this bed, although the latter are fairly common in 

 all the overlying strata. 



A few derived Chalk fossils have been found by us in the flints, 

 from the gravels, and include (according to Mr. C. D. Sherborn 

 and Mr. T. H. Withers) :— 



Echinocorys vulgaris (= E, scutatus Leske), of the shape characteristic 



of the zone of Micraster cor-tesludinarium.. 

 Inoceramus inconstans (Woods), also a form typical of the same 



horizon. 



The tabular flints so common in the Piltdown gravel are doubt- 

 less derived from the regular layers which occur at the base of the 

 zone of Micraster cor-anguinum, and in the upper part of the 

 zone of M. cor -testu dinar ium. In age, therefore, the derived 

 Chalk fossils and the flints are very similar, belonging to an 

 horizon well exposed at present in the southern Chalk escarpment 

 (as, for example, at Off ham) near Lewes. 1 



Our first work this year was to clear away completely all debris 

 overlying the floor of the dark gravel-bed from the vicinity of the 

 spot where the mandible and piece of occipital bone were found 

 last year, so that the irregularities of its level might be fully 

 exposed. We found that the floor was full of depressions, often 

 measuring 2 to 7 feet across and 1 to 2 feet in depth. Into these 

 depressions had been drifted the dark ferruginous gravel, and 

 in places there yet remained small undisturbed patches. The area 

 so exposed by us measured about 20 feet square. 



Following a small rift or channel in the floor which was yet 

 filled with undisturbed gravel, we discovered another fragment of 

 a tooth of Stegodon bearing three cusps. This specimen was 

 worked out very carefully, and preserved in the gravel matrix. It 

 seems probable, from its general appearance and condition, that 

 this fragment is a portion of the same molar as that to which 

 the two fragments found last year belonged : like them, it is 

 shattered, and shows little sign of rolling. If so, it must have been 

 broken before its original deposition, and not by the workmen. 

 The other portions were found about 10 yards away, in debris 

 composed of the dark gravel. 



In a depression adjoining that in which a portion of the human 

 mandible occurred, was found what appears to be a flint-flake 

 roughly worked on one face and stained dark brown (PI. XIV, 



1 ' Cretaceous Bocks of Britain : the Upper Chalk ' Mem. Geol. Surv.. 

 vol. iii (1904) pp, 46-47. 



