128 
LECTURE X. 
'vvith numerous, round, concave cups, or suckers^ 
which adhere so strongly to whatever substance 
the animal chuses to attach itself to, as not to be 
separated without great force. 
Exclusive of these characters, the animals of 
this genus are furnished with an internal pouch or 
receptacle, filled with a very dark- coloured fluid, 
in some species intensely black : this fluid they 
discharge at pleasure through a tubular orifice 
situated at the base of the breast. 
The most common European species of this 
genus is the Sepia Officinalia of Linnasus, generally 
known by the name of the Cuttle-Fish. This ani- 
mal, which, at its full growth, measures about two 
feet in length, is of a pale bluish-brovvn colour, 
with the skin marked by numerous dark-purple 
specks. Imbedded in the back or fleshy part of 
the body of this species is always found a large 
oblong-oval, calcareous bone, of a cellular tex- 
ture, and which is of so light a nature as to float 
in water. It has been supposed that the animal 
has the power of filling the minute cellules of this 
bone with air, or of exhausting them of it at plea- 
sure, in order to ascend or descend with the great- 
er facility. This bone of the Cuttle-Fish is often 
