268 Rev. 0. Fisher — On a Worked Flint from Cray ford. 



alternations of the different drifts, but only in certain spots, and not 

 over large tracts. Such, alternations are well exemplified in the 

 drift cliff bounding the plain of Limerick on the west; the succeeding 

 hot and cold years being registered by gravels and Boulder-clays, 

 (not necessarily separate members but rather parts of a whole) all 

 merging one into the other ; yet I believe an ardent theorist could 

 conveniently prove that instead of there being one Boulder-clay 

 period in that district, there were six or eight, with about an equal 

 number of periods of " middle gravel." 



In conclusion, I wish to point out, as it seems not to be generally 

 known, that the "Esker gravels" of the central plain of Ireland 

 lie on the Boulder-clay-drift, in which the principal blocks and 

 fragments are more or less rounded, and usually of limestone, while 

 in the vicinity of the hills and mountain groups the eskers (Anglice 

 ridges) continue on to the Boidder-drift. The latter drift is always 

 more or less local in character, contains more or less angular and 

 subangular blocks and fragments, always overlies the Boulder-clay 

 drift, and in places merges into the moraine drift found in the mountain 

 valleys. 



VIII. — On a Woeeed Flint fbom the Bkick-eakth of Ceayford, 



Kent. 

 By the Rev. 0. Fisher, F.G.S. 



DUEINGr a visit to Crayford in April, under the guidance of my 

 friend Mr. Dawkins, I obtained a worked flint from Slades 

 Green Pit. The discovery seems worth recording, on account of the 

 presumed early age of the deposit in which it occurred. Mr. Evans 

 has kindly looked at the specimen, and considers it decidedly to have 

 been worked, so that there is no room for doubt upon that head. 

 I picked the implement out of a band of rounded flint gravel, lying 

 beneath the sandy stratum which contains abundance of shells, and 

 among them the Gorbicula (or Cyrena) fluminalis and TInio litoralis, 

 together with many mammalian remains. The section was roughly 

 as follows : 



North Hast end of Slades Green Pit. ft. in. 



Trail of Clay (about) 6 



Sandy brick-earth with freshwater shells 5 



Pebbly band with worked flint 5 



Gravelly brick-earth ... 6 



It appears probable that the layer of gravel in which the worked 

 flint occurred is on the horizon of No. 2 in Mr. Dawkins' section, 

 fig. 3. (see Quart. Journ. Geol. Soc, Lond. 1867, vol. xxiii., p. 96.) 



As far as I know, this is the first instance of obtaining evidence of 

 the existence of man in this country in association with Gorbicula 

 (or Cyrena) fluminalis. Mr. Prestwich, however, records having 

 found that shell in the implement-bearing gravel of Menchecourt.^ 

 And I think this is the first time of finding anywhere a chipped flint 

 in association with Unio litoralis. 



Rhinoceros megarhinus found here, though not commonly met with 

 in implement-bearing * gravels, is mentioned as occurring at Bedford. 

 1 Phil. Trans., part, ii., 1864, p. 282. ^ j/^ia, p. 284. 



