65 



ridge to the river-gravels which rest upon it, and have protected 

 the underlying chalk from denudation ; the bottom therefore of 

 the ancient valley is here preserved, while the hills and slopes 

 which once formed its sides have been long since destroyed and 

 washed away. The dotted lines in Fig. 4 (kindly lent by H.M. 

 Geol. Survey) will give an idea of the probable configuration of 

 the country at the time when these beds were deposited. 



Fig. 4. Section across the Wilbraham Gravels. 

 Droveway. Eoad. Eoad. Stream. Bottisham. 



Horizontal scale, 2 in. to a mile. Vertical scale, 200 feet to an inch, 

 a = chalk. h = ancient river gravel. c = gi'avels of Wilbraham Fen. 



Some small excavations north-west of Great Wilbraham Hall 

 exposed about 9 feet of rough flint gravel and sand ; from the 

 bottom of one of the pits I obtained the tooth of a deer, and 

 was told that bones were frequently found. The stones here 

 had lost some of their angularity, and the further the distance 

 from the hills, the more rolled and rounded do the pebbles 

 become, affording, were it needed, another proof of the fluviatile 

 origin of the beds. The sand-pit by the wood opposite the Hall 

 is at a lower level, and is probably near the spot where the 

 Wrattiug Valley stream joined that we have been tracing, the 

 channel of the former being intersected by the Avatercourse 

 running westward from the present springs. 



Close by Little Wilbraham Church there is an extensive 

 pit, the recent diggings in which show loamy sand and sandy 

 gravel, the former containing in one place small specimens of 

 Saccinea and Fisidium. Gravel has also been obtained from 

 numerous holes dug in the fields north of Little Wilbraham, 

 and a bed of loamy marl overlying gravel in one of these yielded 

 several specimens of Succinea, Helix and Pupa ; bones also are 

 said to have been found. The ridge here is about half a mile 

 wide, but it becomes somewhat narrower to the N.W., where the 

 above section (Fig. 4) is taken, to show its relations to the 

 present surface of the ground, and especially to Wilbraham Fen. 



