Ilium (bone) "ilis"), meaning "groin" or "flank". The ilium consists of the body and wing. Together with the ischium and pubis, to which the ilium is connected, these form the pelvic bone, with only a faint line indicating the place of union. The body () forms less than two-fifths of the acetabulum; and also forms part of the acetabular fossa. The internal surface of the body is part of the wall of the lesser pelvis and gives origin to some fibers of the obturator internus. The wing () is the large expanded portion which bounds the greater pelvis laterally. It has an
Petrous part of the temporal bone smooth and rounded, and it leads into the internal auditory meatus a short canal, about 1 cm. in length, which runs lateralward. It transmits the facial and acoustic nerves and the internal auditory branch of the basilar artery. The lateral end of the canal is closed by a vertical plate, which is divided by a horizontal crest, the falciform crest, into two unequal portions. Each portion is further subdivided by a vertical ridge into an anterior and a posterior part. Behind the internal acoustic meatus is a small slit almost hidden by a thin plate of bone, leading to a