late 82. 
MOLLUSCA. CEPHALOPODA. HELICINA. 
The Mollusks are inarticulated animals, mostly with a shapeless body, the head and 
body only being distinct in the more highly organised genera; they have no skeleton or 
callous covering whatever. The body is enclosed in a loose, wrinkled skin, which can be 
distended at will in any direction. In many of the genera the eyes are wanting; the ali- 
mentary apparatus on the other hand being especially well developed. Some of the mollusks 
are naked, such as the cephalopods and some of the gasteropods, while others form a shell 
for themselves with the calcareous matter exuded from the skin, which however only ad- 
heres loosely to the body. Most of the mollusks are marine animals, though some genera 
are found in fresh water and others on dry land. 
In the Cephalopods the head is quite distinct from the body. The large mouth is sur- 
rounded by a circle of muscular arms, from four to ten in number, provided with suckers, 
which serve for locomotive purposes or to enable the animal to grasp its prey or to attach 
itself to foreign bodies. A large staring eye is situated at each side of the head. Most of 
the cephalopods are provided with a gland, the so-called inkbag, which furnishes the brown- 
black pigment know to painters by the name of sepia. This liquid can be ejected at plea- 
sure and serves as a protection to the animal by clouding the water and thus obscuring its 
retreat when pursued. 
| 1. The Octopus Vulgaris, or common Octopod has 8 feet or arms, as its name implies, 
and is found in all the European seas. Its color varies ftom a white-grey to a dark brown, 
according as it is in a quiescent or an irritable condition. It lies in wait for its prey con- 
cealed among the rocks under water. 
2. The Eledone Moschata has the faculty of varying the shape of its body at will, at 
times appearing like a.loose bag or assuming a pointed or egg-shaped form; it is also ca- 
pable of changing its color. This species is only found in the Mediterranean on a muddy 
bottom, where it is very common, and, in spite of its pronounced musky flavor, is much 
used as an article of food by the poorer classes. 
3. The Paper Nautilus, Avgonauta Argo, is a most beautiful and delicately colored 
animal, inhabiting an elastic shell, as thin as paper, but which is not in any way adherent 
to or connected with its body. It is remarkable for its peculiar method of sailing over the 
sea, using six of its tentacles as oars and the other two membranous ones for sails. On the 
approach of danger or rough weather it draws in all its arms and sinks to the bottom. 
It is found in the Mediterranean, especially on the coast ot Sicily. 
4, The common Cuttle-fish, Sepia Officinalis, belongs to the family of the Decapods, 
or ten-footed mollusks, and is very common in the Mediterranean near the shore. The soft 
_parts of the animal are supported by a firm calcareous bone, the well-known cuttle-bone, 
which is found on our coasts. 
5. The Flying Squid, Lofigo Sagitta, has a long, narrow body, enclosed in a sort of | 
sheath, which spreads out at the tail into a broad fin-like appendage. It has a delicate, 
transparent backbone, in shape like a pen, whence it is commonly known as the ‘penfish’. 
It is most ce ame colored. — 
The Snail family, Helicina, is distinguished by a more or less well-developed head and 
by the eyes being placed at the tips of the long horns or feelers. The mouth is also most 
peculiar in its arrangement, there being a pair of sharp, dentated lips while the tongue is 
also covered with a number of small teeth. They move themselves slowly along by means 
of the large foot or disc which extends over the greater part of the under side of the body. 
Most of the snail tribe are marine animals, furnished with gills; while the land snails, 
| though furnished with lungs and breathing air, also require a certain amount of moisture. 
6. The Road-Slug, Limax Rufus, has no shell and belongs therefore to the subfamily 
of the nudilimaces or naked snails. It is a very well-known genus. 
7. The Great Water-Snail, Limneus Stagnalis, is found in stagnant water. Its shell, 
which is ae coated with mud, attains the length of 2% inches. 
8. The Marsh-Snail, Paludina Vivipara, is found in ditches and ponds. The young 
are brought forth furnished with shells. 
9. The Helix Carocolla is one of the most beautiful types of tropical snails. It is 
found in the Antilles. 
10. The Oliva Elegans is found in the southern seas. Its shell, which is closely rolled 
together, has a number of short whorls at the end. It has a very broad foot, which extends 
beyond the head. 
11. and 12. represent two beautiful specimens of the Conus: C. Cedonulli and C. Achatina. 
The species are very numerous, some 400 varieties being known. They are found in the southern 
and tropical seas and are much sought after by collectors on account of their beauty, very high 
prices being sometimes paid fer them, The animal has a long, narrow foot and a small head. 
