406 



THE GEOLOGIST. 



Average 

 thickness. 



pliant and of species of liorse, ox, and deer, generally 

 near the base. This bed is fiu'ther remarkable for con- 

 taining the Tvorked fliats ("haches" of M. de Perthes, 



and "langues des chat" of the workmen) 6 to 12 feet. 



resting on 

 Uneven surface of Chalk strata. 



In the stratum 2Z> the flint implements are found in considerable numbers. 

 Mr. Prestwich tells us in his paper read before the Royal Society, that on his 

 first visit he obtained several specimens from the workmen. The late Dr. 

 Rigollet mentions the occurrence also here in the gravel of round pieces of 

 hard chalk, pierced with holes, which he considers were used as beads. Such 

 were also found by Mr. Prestwich on his visit, and recognized as small fossil 

 sponges iCoscimpora globularls, D'Orb), very common in the Chalk. He ex- 

 presses some doubt about their artificial dressing, although he admits " some 

 specimens do certainly appear as though the hole had been enlarged and com- 

 pleted." We figure a specimen. 



Supposed Fossil Bead. 



These gravel-beds at St. Acheul cap a low chalk hill a mile south-east of the 

 city of Amiens, and are about a hundred feet above the valley of the Somme, 

 and are not commanded by any higher ground. 



Pig. 2 is also from the gravel of Amiens, and is a very good example of the 

 large pear-shaped implements. The specimen No, 2 is a type of another and 

 flatter kind, and was probably used as a javelin, or spear-head, while the largest 

 pear-shaped specimens like fig. 1 were probably used for digging roots, as the 

 upper extremity is unworked, and left bulbous in shape, as if for fitting the palm 

 of the hand when in use. It seems there are two sorts of pear-shaped flOnts, 



Flint Implement (c) lashed to a stout pole {a) by cord {d), as a spear-head; h, notch at end of 

 pole for end of insti'ument. 



and that some were used like fig. 1 as javelin, or spear-heads. Sir Charles 

 Lycll _ha_s in his collection one of these worked flints thus lashed on to a stout 

 pole, in illustration of their probable use as javelin-heads, of which we give a 

 representation below. 



In the gravel deposit on which the to-^-n of Abbeville stands, a number of 

 flint implements have been found, together with teeth of Elephas primigenius 

 and, at places, fragments of fresh-water shells. The section, however, which 

 Mr. Prestwich considers of great interest is that at Menchecourt, a suburb to 



