PLEISTOCENE CLASSIFICATIONS. 275
pre-existence of this deposit is indicated. The bone-bed yielded
a Proto-Mousterian tortoise-core (probably Acheulian date),
in direct association with Elephas primigenius, Bos primigenius,
Felis leo spelaea, Cervus elaphus, Ursus sp eleus, etc. (22).
March (Cambridgeshire) and Nar Valley (23).—In this
district there are marine beds, reaching an elevation of over 50
feet, containing Corbicula see also- page 278), which lie directly
on the Boulder Clay. These are closely associated with river
deposits a little further inland. The oldest of these river
deposits yields the Elephas antiquus fauna. The Chellian,
Acheulian, and Lower Mousterian industries are also recorded
from these gravels ; probably the Chellian are derivative (they
are so at Shrub Hill), while the Lower Mousterian, if correctly
identified, may be from slightly later gravels. The corres-
pondence with Clacton is very close, where the E. antiquus
fauna, with a contemporary Mesvinian (or pre-Mousterian)
industry immediately underlies estuarine sands which lie at an
elevation of about 30 to 40 feet (24).
Hoxne.—In the face of the new Foxhall Road evidence I
do not think anyone can now doubt the probability of the similar
reading of the Hoxne section, but we must await the results of
re-investigation.
Derwent Valley.—The pre-glacial valley is filled with
Boulder Clay, through which the river has cut its present channel.
Associated with this re-excavation, there is a gravel terrace
running for some miles south of Derby, at a regular level of 15
to 20 feet above the present alluvium. A section in this gravel
yielded a number of bones of Hippopotamus which were not
derivative, but well-preserved and belonging to one animal.
There were also 20 species of temperate plants.
The top of the gravel presented the usual phenomena of
trailing referable to the Ponders End cold stage, but the regular
conformity of the gravel terrace to the alluvium, and to the
present river, precludes the occurrence of any serious glacial
episode since the re-excavation of the valley through the
Boulder Clay (25).
Thus, although one must abandon Hornchurch as evidence
(unless a proved palaeolithic deposit can be found there in place),
there are now other evidences to compensate for its loss, par-
ticularly Foxhall Road and High Lodge, where undisturbed
palaeolithic deposits with contemporary implements directly
overlie Boulder Clay.
With especial reference to the Derwent Valley evidences,
it is incredible to me that the Palaeolithic river terraces of south-
eastern England generally could have remained, as we see them
to-day, through the stupendous disturbances of a serious
glaciation.