536 Mollusca. 
species, entirely covered with a fleshy sheath ; in others 
the sheath reaches only to the middle of the body. 
They have eight arms, or rather legs, and in general 
two feelers, much longer than the arms. Both the 
feelers and arms are furnished with strong circular cups 
or suckers. The mouth is hard, strong, and horny, 
resembling in texture the beak of the parrot. The 
body is of a jelly-like substance, and usually covered 
with a coarse skin, having the appearance of leather. 
This skin contains cells of different colours, which are 
capable of changing their relative position, so that the 
Cuttle-fish is able to change the colour of its skin. By 
means of the numerous circular cups or suckers with 
which the arms are furnished, they seize their prey, 
and firmly attach themselves to the rocks. Their 
adhesive power is so great, that it is generally more 
easy to tear off the arms than to separate them from the 
substance to which they are affixed : if the arms happen 
to be broken off, they are soon reproduced. The size to 
which this creature grows has been variously stated; 
and, although evidently exaggerated by some authors, it 
undoubtedly attains to a very considerable magnitude. 
When attacked in its own element, it has been known 
to overcome a large dog. Its jaws are extremely strong 
and powerful, and with its beak it can crush in pieces 
the shells of the fish on which it feeds. In the body is 
a bladder filled with a dark inky fluid, which it emits 
when alarmed, and which not only tinges the water so 
as to conceal its retreat, but is so bitter as immediately 
to drive off its enemies. This inky fluid, when dried, 
forms a very valuable colour, used by artists, and 
known as Sepia. 
The bone, or calcareous plate of the Sepia Officinalis, a 
species common on our coasts, is a well-known substance, 
and is much employed in the manufacture of tooth- 
powder ; and by silversmiths for moulds, to cast their 
small work, such as rings, &c. It is also converted into 
that useful article of stationery, called pounce. 
