My Gray's Anatomy disagrees with one detail - the pubis is not part of the ilium. Each side of the of the pelvis (called an os coxa) is formed of three bones - the ilium, ischium and pubis. The ischium forms the inferior portion of the pelvis, the ilium the 'wings' and the pubis the anterior, inferior portion, terminating in the pubic symphysis at the ventral aspect of the pelvis. These three bones fuse in late adolescence, but are referred to separately. The collective term is, as above, os coxa.