TRITONIA. 125 
they be of an electric nature, they may be the 
means of defending from foreign enemies one 
of the most delicate, defenceless, and beautiful 
Gasteropods that inhabit the deep.” * 
The mouth in this animal forms, according to 
Cuvier’s elaborate description, a cutting instrument 
of peculiar efficiency. “It Gifs: aang 
consists of a large oval iS irae ht 
and fleshy mass enclosing a 
the jaws and their mus- 
cles, as well as a tongue 
covered with spines, and 
its opening is guarded by 
two fleshy lips. The jaws 
form the basis of all this 
apparatus. Their substance is horny, their colour 
a yellowish brown, and their form very extraordi- 
nary, for an organ of this kind cannot be better 
described than by comparing it to the shears used 
in shearing sheep. They differ, however, in the 
following particulars: instead of playing upon a 
common spring, the two blades are formed to work 
upon a joint, and instead of being flat, they are 
shghtly curved. 
“The two blades are very sharp, and there is 
nothing that has life that they cannot cut, when 
the animal causes the cutting edges to glide over 
each other. For this purpose muscles of great 
strength are provided, the fibres of which are trans- 
verse; and their office is to approximate the two 
blades that are again separated by the natural 
elasticity of the articulation, whereby they are 
united at one extremity. 
“The aliment, once cut by the jaws, is imme- 
* Edin, Phil. Journ. xiv. 186. 
MOUTH OF TRITONIA. 
