10 THE ESSEX NATURALIST
(Porat) (♂) was taken in May 1959 at the base of shaft No. 3.
This species does not appear to have been recorded for Essex,
Waterhouse (1901). One example of Brachyiulus pusillus
(Leach) (♀) was taken rapidly crawling on the floor of a chamber
of No. 9, in complete darkness in May 1959. It has not been
recorded from caves and does not appear to have been recorded
for Essex.
In 1959, the base of shafts Nos. 3 and 5 were fairly closely
examined for beetles (Coleoptera), 60 species being found, though
other species were undoubtedly also present. With very few
exceptions these species are common, ground-dwelling bettles,
previously unknown from caves. The most abundant animals on
the heaps of debris were beetles, particularly Omalium rivulare
(Payk), Oxytelus spp., Nargus velox (Spence), Catops fuliginosus
Er., and Proteinus spp. Fairly abundant were Megasternum
obscurum (Marsh.), Catops nigricans (Spence) Omalium caesum
Grav., Conosomus testaceus (F.), and Atheta (Acrotona) fungi
(Grav.). Five or more examples of Feronia madida (F.), Abax
parallelopipedus (Piller & Mitterpacher), Quedius mesomelinus
(Marsh.), and Philonthus politus (L.) were found. In January
1962, at the base of shaft No. 3, only a few Megasternum obscurum
(Marsh.) and some, as yet unidentified, Atheta spp. were found.
Only two beetles have been found away from the shafts, both in
May 1959. A single specimen of Catops fuliginosus Er. (♂) was
found running on the wall of a chamber of No. 10, and in a tunnel
then being dug, and now joining No. 9 to No. 17, a single specimen
of Quedius mesomelinus (Marsh.) was taken. Both these species
have been recorded from caves.
Several spiders and mites (Arachnida) have been seen at the
base of the open shafts, and four species have been identified;
they are all common, but have not been recorded from caves.
At the base of the open shafts, earthworms and centipedes
have been seen, but none collected. No species of Collembola
have been observed. In January 1962, but not on previous
occasions, a number of large flies, mostly inactive, were seen in
the chambers of No. 5. These have not yet been identified. Dung
flies and mosquitoes, etc., are known to hibernate in caves. The
only species of invertebrate commonly found in the dark chambers,
with the exception of bat ectoparasites, is a small gnat, which has
not been identified. Gnats were seen flying in a number of
chambers, which are remote from the entrances, on both visits,
though fewer were seen in January 1962. Empty pupal cases have
been found attached to the walls, but although the floors of the
chambers, where these have been found, have been closely
searched, no larvae have been discovered. These gnats are,
perhaps, the only invertebrate troglobites to be found in the
deneholes.
Any discussion of food-cycles should centre around the flora of
the holes, Newrick (1957). However, this is not possible here as
no collecting of fungi, or sampling of bacteria has been performed;