52 
dages of the foot. The head terminates in a short 
non-retractile muzzle, with long tentacles and_ short 
stalked eyes. The three following species belong to 
the same family. 
Fig. m. Zrochus marmoratus; fig. n. Turbo 
olearius, and fig. o. Nerita exuvia are three shells 
from the Eastern Seas which ate very unlike in ap- 
pearance. Zvochus has a conical shell with a lozenge- 
shaped mouth, while Zz7o has a round one. 
The Wentle-Traps (Scalaria pretiosa fig. p and 
S. communis fig. q) represent another large group, 
in which the shell is thick and spiral. The mouth 
is oval, and the outside is adorned with vertical 
ridges. The first species is European, and the second 
Indian. The animals have 4 long slender tentacles 
at the base of which the eyes are placed; the tongue 
is armed with rows of numerous small teeth. 
There is a large group of shells distinguished 
by a long retractile proboscis. The animals are all 
carnivorous and some possess shells of beautiful 
shape and colour. 
Fig. r. Voluta ethiopica is a thick shell with 
a short whorl, and a deep excavation for a tube (or 
siphon) leading to the gills. 
Fig. s. Harpa ventricosa, the Harp Shell, is 
an inflated ridged shell with a short whorl. 
Fig. t. Altra episcopalis, the Mitre Shell, is a 
native of the East Indies. 
Plate XXI (left side). 
Fig. a. Murex trunculus, the Rock-shell, has 
at least three rows of swellings and spines. It is 
sometimes eaten, and its operculum was formerly 
used in medecine. The allied genus Purpura was 
Order II. 
These lung-breathing molluscs are inhabitants 
of the land and of fresh water. The trachea is con- 
nected with a network of vessels, and opens ex- 
ternally on the right side. The heart lies behind 
the lungs. They are all hermaphrodite, and most 
of them lay eggs. The eyes are situated either at 
the extremities of the tentacles, or at their base. 
The first group is illustrated by the 4 following species. 
Fig. k. Limnea stagnalis, the Water-Snail, is 
a dull-coloured species which is very common in 
stagnant water. In some of the allied species found 
in the same localities, the whorl of the shell is 
shorter and the mouth is larger. The animals 
creep on plants, or swim on the surface of the water 
with the shell downwards, and the foot upwards. 
The white gall-like clusters of eggs are often to be 
seen fixed to water-plants. 
In the genus FYanorbzs, the shell is rolled into 
a flat disc. They are found in the same localities 
as the Water Snail. The commonest species is 
Flanorbis corneus (fig. 1). In a smaller kind (P. 
carinatus, fig. m) the shell is ridged. 
Fig. n. Scarabus imbrium has a thick shell, 
and lives in damp places, where it sometimes makes 
its appearance suddenly in large numbers. 
The Slugs have 4 retractile tentacles, the hinder 
pair of which are furnished with eyes at the tips. 
The shell is reduced to a small rudiment beneath 
the skin. They are land animals, and are found in 
damp places. We have figured two species, the Garden 
Slug (Limax hortensis, fig. p) and the Red Slug 
(Arion rufus, fig. 0). The latter is common in woods. 


once of far greater value, as the source of the costly 
Tyrian Purple dye; but its use has now been re- 
placed by that of aniline dyes. 
Fig. b. Conus ammiralis represents another 
large genus of shells. The tongue is set with two 
rows of long hollow teeth, which can be darted out 
of the mouth like arrows. 
The last group of the marine Branchzata which 
we shall notice have a ribbon-shaped tongue, two 
tentacles, and spiral shells. In the Cowries (Cypr@a) 
the shell is oval, the mouth is long and deeply 
ridged on both sides, and the lips are recurved. 
Fig. c. Cyprea tigris is a fine showy species, 
but C. moneta (fig. d) is of greater importance, as 
it has been used throughout Africa as money from 
time immemorial. Whole caravan-londs are annually 
sent from Zanzibar into the interior of Africa, and 
on the West Coast a great trade is carried on with 
cowries, which are said to be worth about 700 to 
the shilling. 
Big: ie: 
with raised circular ridges. 
used as a trumpet. 
Fig. f. Cassts tuberosa. In this species the 
whorl is short, the last curve of the wide shell is 
large, and the opening narrow. 
Fig. g. Dolium galea, a native of the Medi- 
terranean, presents opposite characters, for the shell 
is thin, and the mouth wide. 
Fig. h. Strombus auris Diane and fig. i. S. pugzlis 
have a pointed whorl, and the outer lip has a broad 
wing-shaped expansion. In the animals the foot is 
divided into two parts, opposed to each other, and 
the animal is thus enabled to leap. 
Tritonium nodiferum is a long shell 
In old times it was 
Pulmonata. 
The second division of the Pudmonata includes 
the shell-bearing snails. They have 4 tentacles with 
eyes at the tips, and large spiral shells in which the 
coiled intestines extend to the tip, and into which 
the animal can completely withdraw itself. 
Fig. q. Pupa uva belongs to the smaller spe- 
cies, in which the shell is cylindrical, and (in the 
species figured) ribbed. They are found under moss, 
and several species are viviparous. 
Fig. r. Bulimus decollatus has rather a curious 
habit, for as the animal grows, it withdraws itself 
from the last coil of the whorl, and closes it by a 
partition, when the empty coil falls off, and leaves 
the shell sharply truncated. This species inhabits 
Southern Europe. 
Fig. s. Helix pomatia, the Edible Snail, re- 
presents the important genus He/zv, in which the 
whorl of the shell is all but invariably turned to 
the right. In autumn the snails retire to their winter- 
quarters under moss, and close the shells for six 
months with a calcareous operculum. The snail is 
considered fit for food as long as it is closed, and 
is eaten in large quantities in many parts of Europe. 
Fig. t. Helix nemoralis is abundant in Eng- 
land, where the Edible Snail is scarce ; and although 
it is a very variable species, it may be recognised 
at once by its chestnut-brown lip. 
Plate XXIL. fig. i. Dentalum vulgare is a curious 
shell found on the coasts of Western Europe, which 
resembles an elephant’s tusk. The shell is completely 
filled by the living animal, but is generally found 
empty, as the creature buries itself in the sand. 
