394 Royal Society .— 



gentleman's opinion, that they there also occur in beds of undisturbed 

 sand and gravel. 



At Moulin Quignon, and at St. Gilles, to the S.E. of Abbeville, 

 the deposit occurs, as at St. Acheul, on the top of a low hill, and 

 consists of a subangular, ochreous and ferruginous flint-gravel, with 

 a few irregular seams of sand, 12 to 15 feet thick, reposing upon an 

 uneven surface of chalk. It contains no shells, and very few bones. 

 M. de Perthes states that he has found fragments of the teeth of the 

 elephant here. The worked flints and the bones occur generally in 

 the lower part of the gravel. 



In the bed of gravel also on which Abbeville stands, a number of 

 flint-implements have been found, together with several teeth of the 

 Elejihas primigenius, and, at places, fragments of freshwater shells. 



The section, however, of greatest interest is that at Menchecourt, 

 a suburb to the N.W. of Abbeville. The deposit there is very 

 distinct in its character ; it occurs patched on the side of a chalk 

 hill, which commands it to the northward ; and it slopes down under 

 the peat-beds of the valley of the Somme to tlie southward. The 

 deposit consists, in descending order, of — 



Average thickness. 



1. A mass of brown sandy day, with angular fragments of 

 flints and chalk rubble. No organic remains. Base very 



irregular and indented into bed No. 2 2 to 12 ft. 



2. A light-coloured sandy clay (" sable gras " of the work- 

 men), analogous to the loess, containing land shells, 

 Pupa, HelLv, Clausilia of recent species. Flint-axes and 

 mammalian remains are said to occur occasionally in 



this bed 8 to 25 ft. 



3. White sand ("sable aigre"), with 1 to 2 feet of subangular 

 flint-gravel at base. This bed abounds in land and fresh- 

 water shells of recent species of the genera Helix, Succinea, 

 Cyclas, Pisidium, Valvata, Bithynia, and Planorbis, to- 

 gether with the marine liuccinum undatum, Cardium 

 edule, Tellina solidula, and Purpura lapilhis. The author 

 has also found the Cyrena consobrina and Littorina rudis. 

 With them are associated numerous mammalian remains, 



and, it is said, flint-implements 2 to 6 ft. 



4. Light- coloured sandy marl, in places very hard, with 

 Helix, Zonites, Succinea, and Pupa. Not traversed 3 -H 



The Mammalian remains enumerated by M. Buteux from this pit 

 are Elephas primigenius, Rhinoceros tichorhinus, Cervus somo- 

 nensis?, Cervus tarandus prisciis, Ursiis speleeus, Hycsna spelcea. 

 Bos pri7)ii genius, Equus adamaficus, and a Felts, It would be 

 essential to determine how these fossils are distributed — which occur 

 in bed No. 2, and which in bed No. 3. This has not hitherto been 

 done. The few marine shells occur mixed indiscriminately with the 

 freshwater species, chiefly amongst the flints at the base of No. 3. 

 They are very friable and somewhat scarce. It is on the top of this 

 bed of flints that the greater number of bones are found, and also, 

 it is said, the greater number of flint-implements. The author, 

 however, only saw some long flint flakes (considered by M. de 

 Perthes as flint knives) turned out of this bed in his presence ; but 

 the workmanship was not very clear or apparent ; still it was as 

 much so as in some of the so-called flint knives from the peat -beds 



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