THE FOOT-JAWS AND THE JAWS. 23 
is longer than the rest, and strongly toothed along the 
inner edge, or that which is turned towards its fellow. 
It is obvious that these two limbs are well adapted to 
crush and tear whatever comes between them, and they 
are, in fact, jaws or organs of manducation. At the same 
time, it will be noticed that they retain a curiously close 
general resemblance to the hinder thoracic legs; and 
hence, for distinction’s sake, they are called outer jfoot- 
jaws, or external mawillipedes. 
If the head of a stout pin is pushed between these 
external maxillipedes, it will be found that it passes 
without any difficulty into the interior of the body, 
through the mouth. In fact, the mouth is relatively 
rather a large aperture; but it eannot be seen without 
forcing aside, not only these external foot-jaws, but a 
number of other limbs, which subserve the same function 
of manducation, or chewing and crushing the food. We 
may pass by the organs of manducation, for the present, 
with the remark that there are altogether three pairs of 
maxillipedes, followed by two pairs of somewhat differently 
formed maxillg, and one pair of very stout and strong 
jaws, which are termed the mandibles (4). All these jaws 
work from side to side, in contradistinction to the jaws 
of vertebrated animals, which move up and down. In 
front of, and above the mouth, with the jaws which 
cover it, are seen the long feelers, which are called the 
antenne (8); above, and in front of them, follow the 
small feelers, or antennules (2) ; and over thei, again, lie 
