322 Geological Society, 



Ireland, which he described in full, and compared with one another 

 as well as with the Upper Devonian of the Continent and America, 

 giving lists of fossils from the English localities. The sections in 

 Devonshire and South Ireland were contrasted with those in Pem- 

 brokeshire and North Ireland ; and it was shown that, although the 

 physical features in the two cases very nearly correspond, the Mar- 

 wood series is constant, and the Pilton group of the former districts 

 is a series unknown in Pembrokeshire, or only represented by beds, 

 a few feet thick, at the base of the Carboniferous slate. The author 

 endeavoured further to prove the intercalation of marine beds in 

 the Upper Old Red Sandstone, and, by the fossils, the correlation of 

 the Marwood Group of Devonshire with the Uppermost part of that 

 series. He stated his belief in Sir R. I. Murchison's suggestion, 

 that the Caithness Flags belong to the Middle, and the Cephalaspis- 

 beds of Scotland to the Lower Old Red, which divisions he con- 

 sidered equivalent to the Middle and Lower Devonian respectively ; 

 and concluded by assigning the Tilestones (or Ledbury shales) to 

 the Lowest Devonian. 



June 3, 1863. — Professor A. C. Ramsay, President, in the Chair. 

 The following communication was read : — 



" On the Section at Moulin- Quignon, and on the peculiar 

 character of some of the Flint Implements found there." By J. 

 Prestwich, Esq., F.R.S., F.G.S. 



The recent discovery of a human jaw and of flint implements of a 

 peculiar type and fresh appearance at Moulin- Quignon has led to 

 questions having been lately raised as to the age of the gravel- beds, 

 and the antiquity of these remains. Mr. Prestwich showed how con- 

 flicting had been the evidence in support of the views formerly 

 entertained, and dwelt upon the appearances which had raised the 

 doubts as to the genuineness of certain implements and the fossil 

 nature of the jaw. He also gave a resume of the proceedings of the 

 Conference lately held at Paris and Abbeville, and remarked that 

 the intrinsic evidence appeared to prove the spurious nature of the 

 objects, while the evidence derived from the study of the beds had 

 led to the opposite conclusion. 



The author then showed that, from the physical configuration of 

 the district, corroborated by the presence of extinct mammalia dis- 

 tinctly of contemporaneous age, the modern age assigned to these 

 beds by some geologists could not be maintained, and that, from 

 the occurrence of freshwater shells in both the high- and low-level 

 gravels, their formation must have been due to river-action, and not 

 to a wave of translation or other modification of marine action. 



Mr. Prestwich concluded by stating that, whatever may be the 

 conclusions drawn from the jaw and the flint implements, the age of 

 the deposits is to him perfectly well determined as being of the early 

 quaternary or post-pliocene period, older than the Menchecourt 

 gravels, and anterior to the excavation of the valley of the Somme ; 



