46 
HELIX. 
GENERIC CHARACTER: The shell orbicular, convex 
or conoidal ; sometimes globular, the spire rather elevated ; 
aperture entire, transverse, very oblique, contiguous to the 
axis of the shell; the margins disunited by the projection 
of the penultimate whorl. 
Helix is distinguished from Pupa by the general form °jj 
the shell, which is never cylindrical, and by the borders ot 
the aperture being disunited ; from Bulimus by the aperture 
being rather transverse than longitudinal, and its plane very 
oblique, and almost perpendicular to the axis of the spire ; 
and from Planorbis by the left margin of the aperture being 
contiguous to the axis of the shell, whereas in that genus d 
is very remote from it. The right margin, in the adult Helix- 
is reflected outwards, contrary to what occurs in aqnaii® 
shells. Helix is readily known by the projection of tb® 
penultimate whorl into the aperture. Journal of Science* 
vol. 15, p. 237. 
Mr. Gray denominates the family Helicid®, and charac- 
terizes the genus Helix; shell globose or depressed; mouth 
semilunar; peristome rather thickened and reflected. 
* H. ASPERSA. H. Hortensis. Tort. Lin. Pen. Brit. 
Zo., vol. 4, pi. 84, fig. 129. II. A. Mont. Test. Brit> 
vol. 2, p. 407. Flern. Brit. An., p. 263. Gray’s Turt < 
p. 128, pi. 4 , fig. 35. Snail. Common. 
* H. HORTENSIS. Mont. Test. Brit., rol. 2, p. 4 1 2- 
264. Gray’s Turt., p, 130, ph 
Pen. Brit. Zo., vol. 4, 
Stetf- 
. p. 137. 
Mont. Test. Brit,, vol. 2, p. 4ll' 
K' 1 Gray’a Turt., p. 132, pi. 
264. 
Flem. Brit. An., p. 
fig. 24. Common. 
- H. NEMORALIS. 
Elem., vol. 2, p. 414. 
Flem. Brit. An., p. 
fig. 23. Common. 
* II. PISANA. II. Zonaria. Pen. Brit. Zo., vol. 4, ph 
fig. 133. II. Cingenda. Mont. Test. Brit,, vol. 2, p. 41®’ 
U. P. Fern. Brit. An., p. 259. Gray’s Turt., p. 15“* 
pi. 4, fig. 30. The only place in the west of England |0 
which this shell is found, is at St. Ives, chiefly about tb® 
promontory north of the town ; where it exists in p r °' 
fusion. A sandy soil is perhaps necessary to its existent® - 
* H. RUFESCENS. Mont. Test. Brit., vol. 2, p. 4*3°' 
Flem. Brit. An., p. 261. Gray’s Turt., p. 156, pi* 3 ’ 
fig. 28. Common. 
* H. HISPIDA. Mont. Test. Brit., vol. 2, p. 423, Fle«|' 
Brit. An., p. 261. Gray’s Turt., p. 154, pi, 4, fig- ^ j 
This species seems to be thinly scattered. Montagu fo® 1 ! 
it in some plenty near Penryn ; and I have obtained if itl 
my own neighbourhood. 
