164 SECTION ACROSS THE VALLEY OF THE OUSE. CHAP. ix. 



French types figured at pp. 114, 115. Both specimens were 

 thrown out by the workmen on the same day from the lowest 

 bed of stratified gravel and sand, thirteen feet thick, containing 

 bones of the elephant, deer, and ox, and many fresh-water 

 shells. The two implements occurred at the depth of thirteen 

 feet from the surface of the soil, and rested immediately on 

 solid beds of oolitic limestone, as represented in the accom 

 panying section. 



Fig. 23 



Section across the Valley of the Ouse, two miles WNW. of Bedford. 



1 Oolitic strata. 



2 Boulder clay, or marine northern drift, rising to about ninety feet 



above the Ouse. 



3 Ancient gravel, with elephant bones, freshwater shells, and flint im 



plements. 



4 Modern alluvium of the Ouse. 



a Biddenham gravel pits, at the bottom of which flint tools were 

 found. 



I examined these pits, in 1861, in company with Messrs. 

 Prestwich, Evans, and Wyatt, and we collected ten species of 

 shells from the stratified drift No. 3, or the beds overlying 

 the lowest gravel from which the flint implements had been 

 exhumed. They were all of common fluviatile and land 

 species now living in the same part of England. Since our 

 visit, Mr. Wyatt has added to them Paludina marginata 

 Michaud (Hydrobia of some authors, see p. 225 infra), species 

 of the South of France no longer inhabiting the British Isles. 

 The same geologist has also found, since we were at Bidden- 

 , ham, several other flint tools of corresponding type, both there 

 and at other localities in the Valley of the Ouse, near Bedford. 



The boulder clay, No. 2, extends for miles in all directions, 

 and was evidently once continuous from b to c, before the 



