AT HANGMAN'S WOOD, GRAYS.
259
the deneholes were vacated. Negative evidence is always unsatis-
factory, and we must hope that something more definite will yet
be found in these or like pits. Mr. Holmes has mentioned the
scratchings which covers the lower part of the walls of some of the
deneholes, and he is doubtless correct in supposing them to have been
made by imprisoned dogs in their endeavours to find a way of escape.
There are also some extremely fine irregular grooves covering, like a
delicate network, a large portion of some of the higher and more
inaccessible parts of the walls, the cause of which was not at first
evident; but when it was remembered that the open "holes" were
inhabited by bats, it seemed extremely probable that these fine lines
were caused by the delicate claws of the bats, as they fluttered
against the walls, endeavouring to find a projection where they might
alight and hang themselves up, or from which they might creep into
the chinks of the rock to rest.
[The open-shafted deneholes appeared to be very favourite resorts
of bats, notwithstanding the fact that the animals had to descend 50
or 60 feet to reach the chambers, where we often dislodged them from
their temporary hybernacula. At a meeting of the Club on Novem-
ber 29th, 1884, Mr. Miller Christy exhibited the skins of five species
of bats found in the deneholes during the first series of explorations.
Three of the species were common Essex bats, viz., Scotophilia
pipistrcllus, Vespertilio natteri, and Plecotcs auritus. Two species were
rarer— Vespertilio daubentonii and V. mystacinus. The former
appears to be rare in most places, but three or four specimens
were captured by Mr. Christy during our underground labours.—Ed.]
II.—Note on the Fragment of Millstone from a Denehole.
By F. W. RUDLER, F.G.S., Sec. Anthropological Institute.
The fragment of millstone15 found in one of the deneholes is no
doubt derived from the "millstone lava," which, for the last two
thousand years, has been worked in the neighbourhood of the
Laacher See, in the Eifel. About three miles to the south of this
well-known lake are the extensive subterranean workings of Nieder-
mendig, which have yielded vast quantities of the millstone-rock.
There exists in the neighbourhood a large number of funnel-shaped
pits leading to spacious caverns, from which the stone has been
removed, and as these deserted workings enjoy a low and equable
15 Two still smaller fragments of this stone were found during the examination of the cone of
sand, etc., in No. 5 pit. See ante.—Ed.
P 2