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



French types figured at jip. 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, contain- 

 ing 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 W.N.W. 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, fresh-water 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 spe- 

 cies now living in the same part of England. Since our visit, 

 Mr. Wyatt has added to them Faludina marginata Michaud 

 (^Hydrohia 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 Biddenham, 

 several other flint tools of corresponding type, both there and 

 at other localities in the valley of the Ouse, near Bedford. 



The boulder clay, Is 0.2, extends for miles in all directions, 

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



