58 HELICODONTA OBVOLUTA. 
beech stumps, and other hiding places, protected from the wet. Rev.W. A. 
Shaw says it only seems to come out on very wet days, when it crawls 
under logs, ete. ; at other times it is concealed amongst the “caked beech 
leaves or amongst stones.” Mr. L. Dawes has observed that in captivity 
they seem to avoid the light, and after feeding conceal themselves beneath 
the leaves, and do not emerge from their shelter even at mght during 
strong northerly winds. They are quite timid, and retreat instantly 
within the shell when touched. Locard says they live in small colonies 
and are rather common in shady places at different altitudes, but generally 
at more than 1,000 feet elevation, though it is recorded as having been 
found at an altitude exceeding 5,000 feet in the Tyrol. 
Dr. Lindsay, in recording its occurrence in this country, affirmed its 
presence only on the north slope of the South Downs, a belief which has 
in a great measure persisted to the present time; but Mr. Beeston declares 
that individuals are actually more plentiful and finer on the southern slope. 
This species is characteristic of the mountain regions of Central Europe, 
extending to the Pyrenees, and according to Calcara is found in Sicily ; 
and though in this country practically confined to the calcareous hills of 
the South Downs is, in other countries, not restricted to any particular 
geological formation, or to any special environment. 
‘he species still lurks in the recesses of the primeval woodland tracts 
on the slopes of the downs and in ancient parks, often associated with 
Clausilia rolphii and C. laminata var. albina, and dead shells are found in 
spots where repeated search has failed to yield the living animal. Mr. 
Clement Reid remarks that it is really abundant in all suitable localities 
in Sussex as far east as the river Arun, usually occurring on a dry calcareous 
shady soil with a steep slope, and that its rarity is due to the scarcity of 
ancient woodlands, as it is quite absent from the extensive beech-woods 
planted a century ago. 
H. obvoluta is essentially a geophilous and somewhat gregarious species, 
seldom climbing trees except during showery weather, which is the only 
time when it comes out freely in the daytime from its retreats amidst the 
aggregated beech leaves and other places, and crawls freely about. In dry 
weather it hides within the hollows and crevices of decaying stumps, and 
usually in places sheltered from excessive wet. 
The method of locomotion is often very peculiar; the whole length of 
the foot not being applied closely to the surface traversed, but touching in 
three or four places only, the points of contact changing. In this mode of 
progress the animal raises the fore-part of its body and applies the most 
anterior part to the surface, forming an arch, which gradually passes by 
undulatory motion down the body, by the gradual affixing of the fore-part 
of the foot and a corresponding raising of the hind-part of the arch; the 
arch thus travels from the head to the tail, the tail being then lifted up 
and put down as the arch travels down to it. 
Hibernation and Astivation.—It is commonly reported to hiber- 
nate for a long period, commencing as early as September, but this may be 
based upon a misconception, as each time the mollusk withdraws within 
its shell, after feeding, etc., it always secretes the cretaceous epiphragm, 
which hermetically seals up the mouth, and this everyday occurrence has 
been adduced as proof of the mollusk being actually in winter quarters. 
