accumulation of the Camhrldgeslnre Pleistocene Deposits 67 



Cambridgeshire, advocated a change in the direction of the rivers 

 near Cambridge between the formation of the Observatory gravels, 

 and those which he regarded as belonging to the 'present river 

 system.' That such a change occurred is admitted, but the evi- 

 dence points to all the deposits save those of the Barnwell Station 

 terrace having been formed before the river diversion occurred. 



I may now pass on to consider briefly the palaeontological 

 evidence in favour of the order of age indicated above, leaving 

 details for a future paper. 



In the pits of Barnwell village, and of the Milton Road near 

 Chesterton, loams are sometimes exposed at the base of the over- 

 lying gravels. These loams contain Corhiculaflaviinalis, and with 

 it are associated Unio Wtoralis, Belgrandia margiiiata, and Hip- 

 popotamus, On the continent this is recognised as an early 



Fig. 2. 



Section acroiss Cam N. of Cambridge, with higher valley-slopes restored. 

 The figures shew the suggested order of formation of the deposits. Cross- 

 hatching represents modern alluvium of Cam. 



5. Barnwell Station gravels (Upper Palaeolithic 2). 



4. Newer Barnwell village gravels (Upper Palaeolithic 1). 



3. Loams of Huntingdon Koad area. 



2. Observatory gravels (Middle Palaeolithic). 



1. Older Barnwell village gravel and loam (Lower Palaeolithic). 



Z= Buried channel. 



Vertical scale greatly exaggerated. 



palaeolithic fauna of Chellean or pre-Chellean date, and there 

 seems to be no evidence of the reappearance of this fauna at a 

 later date. 



In the Geological Magazine for 1878 (p. 400) Mr A. F. Griffith 

 described the occurrence of a palaeolithic implement from one of 

 the Barnwell pits. A cast of this is in the Sedgwick Museum, 

 and it appears to be of Chellean type. 



Further afield, the occurrence of similar implements at or near 

 fen-level in Swaffham and Soham fens, and at West Row near 

 Mildenhall, and at Shrub Hill near Feltwell, indicates that rivers 

 had excavated their channels to fen-level in those times. 



There are patches of gravel between the higher Chesterton 

 terrace which corresponds to the Barnwell village terrace and the 



