In front of the forceps, there is a pair of limbs which have a different character, and take a different direction from any of the foregoing (_9_). These limbs, in fact, are turned directly forwards, parallel with one another, and with the middle line of the body. They are divided into a number of joints, of which one of those near the base {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 _foot-jaws_ or external _maxillipedes_. 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 cannot 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 _maxillæ_, 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 _antennæ_ (_3_); above, and in front of them, follow the small feelers, or _antennules_ (_2_); and over them, again, lie {24} the _eye stalks_ (_1_). The antennæ are organs of touch; the antennules, in addition, contain the organs of hearing; while, at the ends of the eyestalks, are the organs of vision.