254 
ME. PHESTWICH ON THE GEOLOGY OE THE DEPOSITS 
present any distinct high-level gravel. I am rather disposed, 
however, to consider it possible that the gravel at the Bidden- 
ham pit, where flint implements have been discovered, may 
belong to that series, although not to the highest level; for 
although the ground slopes very gently towards Bedford, and I 
could not mark any break in the continuity or much change 
in the character of the gravel, still, in the distance of \\ mile, 
there is a difference of level of some 20 to 30 feet between 
the Biddenham pit and the gravel adjoining the railway and 
under the town*. There are also apparently certain slight 
differences in the fauna. At Biddenham the remains of the 
Hippopotamus have not yet been met with, whereas in the J 
railway-cutting near the town they were very abundant. The ^ 
profusion also of the other mammalian remains at the latter | 
place is in marked contrast to their rarity at the former. § 
I have traced the gravels with similar conditions of structure ° 
above Bedford, as far as Olney and Wolverton, and in descend- ~ 
ing the river I have followed them at intervals as far as Lynn. ^ 
At Offord, 3 miles S. of Huntingdon, there is a well-marked low *§ 
terrace of gravel, in which a large number of mammalian re- s 
mains were found during the making of the Great Northern « 
Kailway ; and at Hemingford, 2^ miles E. of Huntingdon, a | 
freshwater deposit with mammalian remains has been de- .§ 
scribed by the Rev. Mr. De la Coed amine f, which I consider ^ 
belongs to the low-level valley series. Jj 
Herne Bay . — I am unable to offer a sufficiently satisfactory 
account and explanation of the position of the flint implements 
found on the shore near Herne Bay. Whether derived from 
a clay drift or from the gravel which caps the cliffs is uncer- 
tain. With respect to that at Swalecliffe, between Herne Bay 
and Whitstable, it would seem to have been derived from a 
freshwater and mammaliferous clay and gravelly sand, belonging 
to a low-level valley deposit and abutting against a cliff 54 feet 
high, on the top of which is a bed of high-level gravel. The 
same gravel may be traced on the other side of the valley at 
* A recent visit to Bedford, and fresh levels taken with the aneroid baro- 
meter, have confirmed this distinction. By taking another line of section, I 
traced the Biddenham gravel to a height of 60 feet above the river, and found 
it separated from the gravel at Bedford by a bare tract of oolitic strata. The section given above (fig. 3) 
embodies these last observations. Mr. Wyatt and Mr. Evans have lately found two flint implements of the 
ovoid or Menchecourt type in the low-level gravel of Summerhouse Hill. — Eeb. 1864. 
t Quart. Journ. Geol. Soc. vol. ix. p. 271 (1853). 
RIVER OUSE 
a. Eecent alluvium. c. Low-level valley-gravel. cl. High-level valley-gravel. 1. Boulder Clay. 2. Oxford Clay. 3. Oolitic series. 
Traces of Loess, in the form of a thin bed of brown sandy clay with angular fragments of flint, overlie both the gravels. (Cot nh ash). 
