The mouth is at the hinder end of a depression called the buccal cavity, and is surrounded by an annular tumid lip, raised into papilliform ridges and bearing a few spines (Fig. 3). Within the buccal cavity are the two jaws. They are short, stump-like, muscular structures, armed at their free extremities by a pair of cutting blades or claws, and are placed one on each side of the mouth. In the median line of the buccal cavity in front is placed a thick muscular protuberance, which may be called the tongue, though attached to the dorsal instead of to the ventral wall of the mouth (Fig. 3). The tongue bears a row of small chitinous teeth. The jaw-claws (Figs. 4 and 5), which resemble in all essential points the claws borne by the feet, and like these are thickenings of the cuticle, are sickle-shaped. They have their convex edge directed forwards and their concave or cutting edge turned backwards. The inner cutting plate (Fig. 4) usually bears a number of cutting teeth. The jaws appear to be used for tearing the food, to which the mouth adheres by means of the tumid suctorial lips. The oral papillae are placed at the sides of the head (Fig. 3). The {8}ducts of the slime-glands open at their free end. They possess two main rings of projecting tissue, and their extremities bear papillae irregularly arranged. The ambulatory appendages vary in number. There are seventeen pairs in _P. capensis_ and eighteen in _P. Balfouri_, while in _P. Edwardsii_ the number varies from twenty-nine to thirty-four pairs. They consist of two main divisions, which we may call the leg and the foot (Figs. 6 and 7). The leg (_l_) has the form of a truncated cone, the broad end of which is attached to the ventro-lateral wall of the body, of which it is a prolongation. It is marked by a number of rings of papillae placed transversely to its long axis, the dorsal of which are pigmented like the dorsal surface of the body, and the ventral like the ventral surface. At the narrow distal end of the leg there are on the ventral surface three spiniferous pads, each of which is continued dorsally into a row of papillae. [Illustration: FIG. 6.—Ventral view of last leg of a male _P. capensis_. (After Sedgwick.) _f_, Foot; _l_, leg; _p_, spiniferous pads. The white papilla on the proximal part of this leg is characteristic of the male of this species.] [Illustration: FIG. 7.—Leg of _P. capensis_ seen from the front. (After Sedgwick.) _f_, Foot; _l_, leg; _p_, spiniferous pads.]