XII.
evidence (which is derived from the Walton Crag), we
may glance at the only other fossils claiming an equal
or higher antiquity. These are the Pliocene skulls
and bones of Calaveras, in California, and the flints
alleged to be implements wrought or used by man and
to have been found in the Miocene limestone of
Beauce, France. But the correlation of the Californian
Tertiaries with European beds is but little more than
surmise, and at most the Calaveras gravels are only
supposed to be of approximately the same age as the
Crag, whilst the flints from Beauce are regarded by
some experts as not of artificial form, and it is even
doubtful if they were really found in the Miocene
limestone.
The Walton specimen consists of one of the common
shells of the Crag—Pectunculus glycimeris—on the con-
vex side of which is carved a rude outline of the
human face. It was found in situ in the cliff, em-
bedded with the concavity upward, so as not to attract
the observation of the fortunate collector to its
transcendent interest, till he came to examine his
spoils. The colour of the cut surfaces and of the sides
of a hole made by some boring mollusc (as is very
commonly the case with Crag shells), is precisely the
same deep ferruginous tint as the natural surface,
whereas the freshly-broken shells are found to be
white inside, the stain being but a film of oxide of iron.
No soluble salt of iron is now present in the Crag,
that could stain a newly-cut or broken shell to the
colour of the specimen in question, even had its posi-
tion in its original place of deposit not been sufficient
to controvert any suggestion of the carving being more
modern than the shell. It may be mentioned that
grains of sand, of a character special to the Crag, are
wedged into the minute crevices of the carving, in a
manner indicating prolonged compression by over-
lying beds. As the cliff is annually receding, the shell
cannot have been laid bare many months before it was
seen, and happily rescued from oblivion.
The idea that man might have been coeval with the
formation of the Crag had been previously suggested,
and the occurrence of shark's teeth pierced at the same
point as is done for necklaces by the natives of the
South Sea Islands, had been advanced in evidence.
But it was answered that sharks' teeth have normally
a line of weakness in the enamel at this point, which
has been taken advantage of by boring molluscs io
Crag times, as by man at present.
The Walton Shell formed the subject of a paper
read to the British Association in 1881 by Mr. H.
Stopes (the present owner of the relic), and in the dis-
cussion which followed, Professor Prestwich stated
that he possessed a phosphatized bone from the Crag,
which had evidently been sawn nearly through and