Hip bone and ischium then become joined, and lastly the pubis and ischium, through the intervention of this Y-shaped portion. At about the age of puberty, ossification takes place in each of the remaining portions, and they join with the rest of the bone between the twentieth and twenty-fifth years. Separate centers are frequently found for the pubic tubercle and the ischial spine, and for the crest and angle of the pubis. Several muscles attach to the hip bone including the internal muscles of the pelvic, abdominal muscles, back muscles, all the gluteal muscles, muscles of the lateral rotator group, hamstring muscles,
Basilar part of occipital bone of the pharynx. On either side of the middle line the longus capitis and rectus capitis anterior are inserted, and immediately in front of the foramen magnum the anterior atlantooccipital membrane is attached. The "upper surface", constitutes the lower half of clivus, presents a broad, shallow groove which inclines upward and forward from the foramen magnum; it supports the medulla oblongata, and near the margin of the foramen magnum gives attachment to the tectorial membrane On the lateral margins of this surface are faint grooves for the inferior petrosal sinuses. Basilar part of occipital bone The basilar part of the