DEPOSI AT BARRINGTON, NEAR CAMBRIDGE. 671 
silty gravels bones and shells occur. Mr. Keeping carried his work 
a few feet further north beyond where the “ coprolite-bed ” runs out, 
and the base of the silt has there begun to rise. 
Diagram of the northern end of Barrin gton Pit. 
a. Trail of fine gravel in which are pits with ashes and bones. 
6. Grey gravelly silt with bones and shells. ¢. Chalk-marl. 
d. Greensand with “coprolites ”’ (2. e. phosphatic nodules). 
e. Gault. 
There is another smaller coprolite-pit, not yet quite filled up, lying 
a few yards to the south-west of the present one. It exhibits a 
little similar stony and gravelly silt, but in patches only, and not 
in situ as deposited, but forming pockets of “trail” with festoon- 
like arrangement and the axes of the pebbles not horizontal. Those 
remnants still existing in the “trail” in this southern pit, as well 
as the manner in which the deposit occurs in the first pit, show that 
the gravel is a portion of a more extended mass, of which the upper 
parts have been denuded away. 
[Since this paper was read a similar deposit, equally rich in bones, 
was laid open for a short time half a mile further up the valley, 
opposite to the blacksmith’s shop on the Green. | 
The materials of which the bone-bearing deposit consists are 
peculiar. The matrix is a grey sand with a slight admixture of 
clay. The pebbles consist of flint in subangular pieces of no great 
size, Sometimes ochreous, sometimes grey, sometimes black. These 
are not rounded, but have their surfaces worn, polished, and the 
angles rubbed off. There are rolled lumps of chalk-marl and a con- 
siderable admixture of “ coprolites,’ as might be expected, seeing 
that the coprolite-bed is abraded by the deposit itself. The remaining 
pebbles are well-rounded pieces of crystalline rocks, consisting of 
quartz, quartzite, syenite, jasper, and trap. These old rocks con- 
tribute a large part of the pebbles, so that the material cannot be 
called a flint-gravel, in that it appears to consist of the least 
destructible parts of the Boulder-clay, mixed with materials from 
the Chalk-Marl and Greensand. 
There are splinters of bone worn smooth at their fractured edges ; 
but most of the bones and teeth are scarcely abraded at all, though 
not often associated. There seems, however, to be reason to think 
that portions of the same individuals have also occurred in proximity, 
although mixed up with fragments of others. Thus one might find, 
222 
