HELIX ASPERSA. EW ( 
We are indebted to Mr. R. W. Goulding, of Louth, for the opportunity 
of reproducing the autograph and the only known portrait of Dr. Lister. 
Diagnosis — Helix aspersa is, with the exception of //. pomativ, much 
the largest of our native snails, and though so distinct in its character, has 
been frequently confused with and recorded for that species by archzeo- 
logists and others. 
From H. pomatia it may be known by its smaller shell, less convex 
whorls, darker colouring, and the rough shagreening of its surface, as well 
as by the flat, brownish, and almost membranous epiphragm. 
INTERNALLY, it is distinguished by the long diverticulum to the stem of 
the spermatheca, the lesser number of digitations to the stylophoric 
mucus glands, and the presence upon the gypsobelum or love-dart of a 
series of crescentic films between the blades, which are quite absent in 
H. pomatia. 
Description.!—The ANIMAL is somewhat bulky, oblong in shape, bluntly rounded 
in front, and attenuated to a point behind ; it is usually of a blackish-grey on the 
upper surface, though oceasionally found of other and paler tints, with about four- 
teen obliqué rows of irregularly oblong TUBERCLES on each side, the summits of 
which are perceptibly paler; towards the FOOT-MARGIN, the junction with the 
mantle and the hinder part of the nopy, the colouring is less dark with often a 
greenish or yellowish tinge, and the granulations become rounder and closer ; the 
paired DORSAL GROOVES, which extend longitudinally along the middle of the back, 
are well defined, and enclose a row of more elongate and noticeably paler tubercles, 
but these furrows do not, asin certain Limaces, terminate in distinet facial grooves ; 
the wenital or lateral furrows extend on the right side from the RESPIRATORY to 
the GENITAL ORIFICE, and on the left side ocenpy a corresponding position ; 
the UPPER TENTACLES are long and slender, with distinct bulbous extremities ; 
the LOWER TENTACLES are shorter, being about one-fourth of the length of the 
upper pair, and almost uniform in thickness ; the MANTLE is blackish-grey, closely 
and finely sprinkled with pale greyish-yellow, and visibly fringing the mouth of 
the shell when the animal is in motion, but its margin is usually coloured in a 
manner corresponding to the markings of the shell. 
The EPIPHRAGM is brownish-grey or greenish-grey in colour, and parchment-like 
in substance, except a small area immediately in front of the respiratory aperture, 
where it is thickened by an opaque-white deposit of lime. 
The SHELL is composed of 445 to 5 whorls, usually more or less obliquely-globose, 
and opaque, with a yellowish or fawn ground colour due to the investing epidermis, 
and irregularly banded and marbled with a 
more deeply-seated blackish-brown pigment ; 
the ordinary character of the banding being 
indicated by the formula 1(23)45; the seulp- 
ture is constituted by strong growth lines, and 
a plexus of coarse, irregular, and deep wrink- 
lings, which resemble shagreen, and become 
stronger and more rugose as growth proceeds ; 
the delicately incised spiral lines of //. pomatia 
are not present in aspersa. The embryonal 
shell or apex, consisting of about 13 whorls, 
is smooth, pale and uniform fawn colour, the 
post embryonal growth only gradually deve- 
loping the distinctive sculpture and markings 
of the species. The lip is reflected and white, 
but sometimes tinted with a fugitive pink, 
and in unusually darkly pigmented shells it 
is occasionally pinkish-purple ; but these tints 
are not permanent, and quickly fade on the 
death of the animal. The UMBILICUS is quite open in half-grown shells, but at 
maturity is entirely covered by a fold and thickening of the pillar lip, and gives rise 
to the subgeneric name Cryptomphalus. 
The height and diameter average 35 mill. ; and the weight about 30 grains. 
Fic. 307.—Shell sculpture or rugosity of 
the body-whorl of //e/7x aspfersa, enlarged. 
1 Refer to vol. i., p. 144 et seq. for fuller descriptions and figures of the general organization. 
