HELICODONTA OBVOLUTA. 59 
Mr. Beeston remarks that it is apparently a hardy species, and can with- 
stand a certain amount of cold. ‘The adults tend to be gregarious, and 
gather together in close proximity im autumn and winter, before retiring to 
their winter quarters in November or December, according to the rigour 
of the season, though reappearing in any milder intervals that may occur, 
the favourite place being heaps of dead leaves and especially the under- 
ground crevices amongst the dead and decaying roots of the moss-covered 
stumps of beech trees, burrowing in such places often to a considerable 
depth, and not secreting the usual epiphragm, which is always present 
when hibernation takes place amongst the leaves above the ground. On 
finally reappearing in the moist days of early spring, the snails climb a few 
feet up the beech trunks, probably to feed upon the small, soft, succulent 
lichens which grow in that position. 
The EPIPHRAGM is thick, white, and calcareous, slightly sunk within the 
aperture, and therefore reproducing the somewhat trifoliate shape of the 
aperture, as well as showing one or even two externally concentric lines of 
growth or secretion. HH. obvolutu, unlike the generality of Helices, does not 
appress and attach the aperture of the shell to the surface upon which it 
is resting by means of the epiphragm, but very frequently, before sealing 
up the aperture, secretes in addition to the epiphragm, a filament of 
mucus rich in lime which emanates from the basal margin of the aperture 
and is affixed to the surface upon which the creature is resting; this fila- 
ment varies in size, and may be 5 mill. in length; the attachment to the 
object rested upon is almost linearly arcuate in shape; it has also a 
broad basis of attachment to the lower lip, and is quite capable of sus- 
taining the animal and its shell. This habit, which resembles that of 
certain Clausiliw and several operculate species, is interesting, and would 
also serve to explain the “ball” of AH. obvoluta said to have been once 
found hibernating socially and “stuck together” in a cluster. It is 
recorded as hibernating at the base of hazel trees, and in hedge banks, 
amongst dead leaves, and in other convenient places. It is not a close 
hibernant, but reappears and feeds in any milder intervals. 
Geological Distribution.—The former wider range of H. obvoluta in 
this country is attested by its occurrence in the fossil state in the Pleisto- 
cene gravels of the Cam, in which neighbourhood it is quite unknown in 
the living state. 
Though the genus existed in the Miocene age, the earliest record of the 
present species is from the Pliocene deposits of Italy, but it has not yet 
been detected below those of Pleistocene age in other countries. 
In Quaternary deposits it is known from many places in Central Europe, 
North Italy, Switzerland, South Germany, the Danubian Valley, ete. 
Upper PLIOCENE.—In Italy, it is recorded by Prof. Sandberger from Castellar- 
quato near Piacenza, Tuscany. 
PLEISTOCENE.—In England, Mrs. MeKenny Hughes records the finding of one 
adult and one immature shell in the gravels of Granchester near Cambridge, the 
specimens being deposited in the Woodwardian Museum. 
In Germany, Dr. Beettger records it as present in the old alluvium of Frankfort, 
Nassau; Dr. Hocken from diluvial sands and ecaleareous tufa near Bruhoden, 
Gotha; Dr. von Ihering from diluvial tufa at Ober-Zaunsbach and Streitberg, 
Franconia ; and by Herr Clessin from the tufa of Regensburg. 
In France, Comm. Caziot records its presence in the Alpes Maritimes, in the 
clays of Villefranche-sur-Mer ; in the tufa of Montigny near Vernon ; and in the 
recent stalagmitic deposit near Vence; Maury and Caziot found it in the tufa of 
Mantega and Magnan; and Mr. G. Neville from the zone of Helix paretiana in the 
