CONTAINING FLINT IMPLEMENTS, AND ON THE LOESS. 
269 
A pit near the Barriere de Vincennes (fig. 13) 
afforded me an excellent example of contorted 
bedding. 
In the valley of the Somme this class of phe- 
nomena is particularly well marked and decisive. 
I know of no place where they are better shown 
than in the pits at St. Acheul (figs. 14, 15). The 
two following sections taken from my former 
paper will illustrate these peculiarities. There 
are two points to be noted, — the one the pre- 
cis. Surface soil and reddish loam. 
b. Eed argillaceous gravel (diluvium rouge). 
c. Light-coloured sandy fossiliferous gravel. 
Fig. 13. 
cis. Surface soil and made ground. cl. Sand and fine gravel with a few shells, 3 to 4 feet. 
b, c. Loam and red gravel, 2\ feet. e. Coarse light-coloured gravel, with mammalian remains, 5 to 8 feet. 
Sections in the gravel-pits of St. Acheul. 
^g- 14. ' pig. is. 
a, b. Soil and brick-earth and subordinate beds of gravel — with Gallo-Roman graves, a', 
c'. Whitish marly sands with land and freshwater shells, containing here and there a few patches of gravel 
and blocks of sandstone, and showing in places fine lamination. 
c. Subangular gravel, in places level, and in other places disturbed, containing numerous blocks of sandstone, 
and large flints not worn : flint implements, mammalian remains, and a few shells. 
sence of large blocks of sandstone, some weighing as much as four to five tons, dispersed 
irregularly through the lower bed of gravel, — and the other the disturbed and con- 
torted condition of the surface of that gravel, and of the bed of sand overlying it. 
These two features are perfectly independent. It is not the presence of the blocks which 
