The _fifth_ (5) has its base flattened and expanded so as to be wedge-shaped, with the apex of the wedge directed proximad. Its dorsal end extends into a tubercle. It thus presents only lateral and medial surfaces. The medial surface shows two tubercles, one distad of the other. The distal tubercle and the distal half of the proximal tubercle are facetted and fit into the sinuous facet on the fourth metatarsal. A narrow facet on the ventral border of the surface articulates with the facet on the ventral border of the lateral surface of the fourth metatarsal. The proximal half of the distal tubercle is facetted for the cuboid (_c_). The lateral surface is smooth, non-articular, and obliquely grooved. _Phalanges_ (Fig. 58, _i_, _j_, _k_).--There are three phalanges in each of the four digits, and these are almost identical with those described for the manus. _Sesamoid Bones._ _Ossa sesamoidea_ (Fig. 58, _l_).--The sesamoid bones are found at the joints between the metatarsals and phalanges, and are in all respects like those of the manus. JOINTS AND LIGAMENTS OF THE PELVIC LIMBS. _Ligaments of the Pelvis._--The ilium and sacrum are articulated at the auricular facet of the ilium and the corresponding rough surface of the sacrum. The joint is an amphiarthrosis, permitting very little movement. A =capsular ligament= surrounds the articular surface, being attached to the bones about its circumference; it is short and strong. Craniad of the capsule is a thick very short ligament, composed of very strong transverse fibres passing from the rough surface of the sacrum to the corresponding rough surface of the ilium. This forms the =lateral iliosacral ligament=, which is united at its caudal border to the capsule. A strong, wide ligamentous band passes from the dorsal border of the ilium to the sides of the sacrum. This is indistinctly subdivided into several bands, which together represent the =long= and =short posterior iliosacral ligaments= of man. _Symphysis pelvis._--The medial borders of the pubis and ilium meet in the middle line ventrad of the pelvis and are here united by cartilage. The joint is strengthened by numerous small bands which pass across the line of junction from one side to the other; these occur on both surfaces. _The Hip-joint._--The hip-joint is an =enarthrosis=, or ball-and-socket joint in which more than half the spherical head of the femur is received into the acetabulum. The depth of the acetabulum is increased by a rim of fibrocartilage about its margin, forming the =labrum glenoidale=. This passes across the acetabular notch, forming the =transverse ligament= of the acetabulum; beneath it blood-vessels and nerves pass into the acetabular cavity. The =capsule of the joint= is large and loose. It is attached about the margin of the acetabulum, and passes over the head of the femur, to be attached to the bone several millimeters distad of the head. It thus encloses both the head and the neck of the femur.