CHAP. viii. MAMMALIA FOUND AT MENCHECOURT. 125 



of the fluvio-marine sands. From the same beds, and in 

 marls alternating with the sands, remains of the elephant, 

 rhinoceros, and other mammalia, have been exhumed. 



Above the fluvio-marine strata are those designated No. 2 

 in the section (fig. 16), which are almost devoid of strati 

 fication, and probably formed of mud or sediment thrown 

 down by the waters of the river when they overflowed the 

 ancient alluvial plain of that day. Some land shells, a few 

 river shells, and bones of mammalia, some of them extinct, 

 occur in No. 2. Its upper surface has been deeply furrowed 

 and cut into by the action of water, at the time when the 

 earthy matter of No. 1 was superimposed. The materials of 

 this uppermost deposit are arranged as if they had been the 

 result of land floods, taking place after the formations 2 and 

 3 had been raised, or had become exposed to denudation. 



The fluvio-marine strata and overlying loam of Menche- 

 court recur on the opposite or left bank of the alluvial 

 plain of the Somme, at a distance of two or three miles. 

 They are found at Mautort, among other places, and I ob 

 tained there the flint hatchet figured at p. 115 (fig. 9), of an 

 oval form. It was extracted from gravel, above which were 

 strata containing a mixture of marine and freshwater shells, 

 precisely like those of Menchecourt. In the alluvium of all 

 parts of the valley, both at high and low levels, rolled bones 

 are sometimes met with in the gravel. Some of the flint 

 tools in the gravel of Abbeville have their angles very 

 perfect, others have been much triturated, as if in the bed 

 of the main river or some of its tributaries. 



The mammalia most frequently cited as having been 

 found in the deposits Nos. 2 and 3 at Menchecourt, are the 

 following : 



Elephas primigenius. 

 Rhinoceros tichorhinus. 

 Equus fossilis Owen. 



