The front portion of the cephalothorax, known as the cephalon, has six segments and includes the eyes and five pairs of appendages. The final three of these six segments can be seen if the animal is turned upside down and the appendages of the thorax (see below) are moved aside. The cephalon segments therefore support, from the front of the animal:
Stalked eyes;
The first antennae, which each have three-segment peduncles (stalks) from which three tactile flagella emerge;
The second antennae, which each have five-segment peduncles and a single, long flagellum;
Mandibles, which are short and hard and are used to grind food;
The first maxillae, which are plate-like (lamelliform), hidden below the second maxillae, and used to transfer food into the mouth; and
Second maxillae, which are similar to the first maxillae but have an additional function. Part of these appendages are constantly beating, thus producing a current of water through the gill chamber to promote the respiratory function of the latter.