Reports & Proceedings — Geological Society of London. 137 



itself. The main differences are: (1) that the Aymestry Limestone 

 is represented by mudstones west of the great fault-line, and (2) that 

 all other divisions show greatly increased thicknesses. 



There is no evidence of any stratigraphical break. On the contrary, 

 the sequence is complete from the Lower Ludlow rocks up into the 

 Old Red Sandstone, and the changes in lithology are usually quite 

 gradual. The oncoming of the Old Red Sandstone conditions is 

 discussed, with regard to their effect on the lithological and 

 palaeontological cliaracters of the strata. 



The extent of Old Red Sandstone, as indicated on present maps, 

 must be greatly restricted, since most of the supposed Old Red 

 Sandstone has been found to belong to the Temeside Group, which 

 in this district attains a great development. The Silurian age of the 

 beds in question is shown by the occurrence in them of Lingula 

 minima, and of characteristic Lamellibranchs, etc., also by comparison 

 with similar strata in the Ludlow area. 



A comparison with other districts in which Upper Silurian rocks 

 are developed shows that deposition attained its maximum along the 

 "Welsh Border, the thickness of the formations decreasing rapidly 

 southwards and eastwards. 



On the east of the district, in the neighbourhood of the great 

 fault-line, the strata are considerably folded along axes ranging 

 north-north-eastwards, parallel to the main fault, with minor faults 

 following the same direction. Away from the major faults the 

 folding is gentler in character, and a series of folds ranging nearly 

 due east and west make their appearance. Farther west the north- 

 north-eastward folding and fracturing reappear. 



2. January 23, 1918.— Dr. Alfred Harker, T.R.S., President, in the 



Chair. 



The following communication was read : — 



" On a Flaked Flint from the Red Crag. " By Professor William 

 Johnson Sollas, M.A., Sc.D., LL.D., F.R.S., V.P.G.S. 



The remarkable specimen forming the subject of the paper was 

 obtained by Mr. Reid Moir from the base of the Red Crag exposed in 

 the brick-pit worked by Messrs. Bolton & Company near Ipswich. 



It is a fragment of a nodule of chalk-flint, irregularly rhombic \x\ 

 outline, with a nearly flat base and a rounded upper surface which 

 retains the whitish weathered crust of the original nodule. 



The base was formed by a natural fracture which exposes the fresh 

 flint bordered by its weathered crust. 



Both upper and under surfaces of the specimen are scored with 

 scrutclies which are mainly straight, but in some cases curvilinear. 



Two adjacent sides have been flaked by a force acting from below 

 upwards, in a manner that recalls Aurignacian or Neolithic workman- 

 ship. The two edges in which the flaked faces meet the base are 

 marked by irregular minute and secondary chipping, such as might 

 be produced by use. On the hypothesis that the flint has been flaked 

 by design, these edges will correspond to the " surface d' utilisation " 

 of M. Rutot, and we should expect to find on the opposite edges of 

 the flint the " surface d'accommodation ", as in fact we do. 



